Geol 101

Geol 101 - Syllabus W ednesday, May 11, 2011 11:52 AM GE0L...

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Unformatted text preview: Syllabus W ednesday, May 11, 2011 11:52 AM GE0L 101 – Summer Session I 2011 Introductory Geology Lecture 11:30 AM – 1:00 PM M-F 05 Mitchell Hall Instructor Information INSTRUCTOR OFFICE HOURS Friday. CS Bartek ( A fter class or by appointment. Emails returned within 24 hours Monday through 1:30 PM Course Objectives When you have completed this course, you should be able to 1. Differentiate the internal structure and composition of the Earth. 2. Differentiate between the three types of plate boundaries. Relate tectonic features to the plate boundaries and processes that formed them. 3. Explain how minerals form and grow from atoms. 4. Explain how igneous, metamorphic, and sedimentary rocks form. 5. Compare how different types of magma form and predict the type of magma and volcanoes that form in different tectonic settings. 6. Explain how rocks weather and compare weathering among different rock types and different environments. 7. Identify strata, faults, and folds in geologic sections and summarize the forces and tectonic settings that lead to their formation. 8. Analyze the geologic history of a cross- section using relative dating principles. Calculate the isotopic age of a rock. 9. Explain what causes earthquakes and earthquake destruction, and apply the correct procedures to locate the source and calculate the magnitude of an earthquake. 10. Compare depositional and erosional environments, features, and processes associated with streams and shorelines. 11. Identify the various parts of the hydrologic cycle. Explain groundwater processes. 12. Evaluate the risks associated with earthquake, volcano, landslide, and coastal hazards. Texts and Other Resources There is one text for this course: Exploring Geology, 2nd edition (2010), by Reynolds, Johnson, Kelly, Morin, and Carter. McGraw Hill Publishers (ISBN -13: 978-007-727040-7) Please buy the textbook the first day of class. You will need it for homework, quizzes and lecture activities. In addition to the textbook, helpful tutorials, animations and Power Points have been posted on the Blackboard site ( ) for this course to help you learn the material. Blackboard Lesson Folders Course materials will be posted in a lesson folder in ―Assignments‖ on the Blackboard website for this course. Each lesson folder contains study guides, helpful websites, quizzes and other assignments. The study guides consist of worksheets with questions for you to answer and problems to solve as you read the textbook and learn in lecture. The questions on the Study Guides will guide you through your reading and will be the basis for the lectures, homework and quizzes and will help you prepare for exams. Course Structure and Requirements Grades: Grades will be awarded on a 1000- point scale. A final accumulation of 750 points = C; 850 points = B; 900 points = A. Geol 101 Page 1 Points One midterm and one final, worth 250 points each 500 (50%) Quizzes and exercises 500 (50%) Total Points 1000 You can check your grades in the Gradebook at the Blackboard site. To do this, go to ―Tools‖ and ―My Grades‖. You will see your total score in terms of percentage. Note that this is a running total. Your grades for quizzes and other exercises will be posted in terms of points, which will be out of 1000. What to do first: Most people find that the most challenging part of summer classes is finding the time to devote to them. So, I suggest that you obtain a planner or calendar and plan a regular time every day that you will devote to your course work. A general guideline of the time required for classroom courses is to spend two hours of study time for every one hour of lecture. Since we are meeting 7.5 hours in this class each week, I estimate that you will need about 15 hours outside of class each week to complete your work. Some students will require less time to learn the material and some will require more. Communication: You can meet with me after class, you can make an appointment to see me before class, and you can email me with questions. All sincere questions are welcome. Communicate with me regularly, including comments, questions and concerns. Please note that course email will go to your UNC Onyen e- mail address. Off- campus users can access their UNC mail using Webmail. You can have your Onyen e- mail forwarded to a different e- mail address by clicking ―Forward email‖ at the Onyen Web site. I s trongly recommend that you use your UNC e -mail account for all e -mails regarding this course. Make sure you regularly check your UNC email and the Blackboard site Monday through Friday for important updates. These are the best ways to contact me: o In person, after class. o E- mail: I answer e- mails between the hours of 9 and 5 Mondays through Thursdays, and between 9 and 1 on Fridays. You can expect an answer back from me within 24 hours from 9 am on Mondays through 1 pm on Fridays . I do not answer email on weekends. E-mail requirements: All e- mail correspondence should contain your full name and ―GEOL 101 Section 001‖ in the subject line. If the e- mail does not contain your full name and ―GEOL 101 Section 001‖ in the subject line, I may mistake your e- mail for spam or for another student and you will not receive a response. Please be professional in your e- mail communications. Professional email includes greetings such as ―Hello, Ms. Bartek‖ and a message written in proper English that clearly states what you want. I really do want to help you, but I reserve the right to delete email that does not adhere to these criteria. Attendance Requirements: Because your attendance in class impacts your learning in this fastpaced course, and the summer school expects me to check attendance daily, the following attendance policy will apply (from the Undergraduate Bulletin): ―Regular class attendance is a student obligation, and a student is responsible for all the work, including tests and written work, of all class meetings. No right or privilege exists that permits a student to be absent from any given number of class meetings.‖ If you are absent when I check attendance, you will be marked absent. Since there are only 25 days in Summer Session I, you are missing 4% of the class for each day you are absent. Therefore, when you have missed 3 classes, the Dean will be notified regarding your absences. Please speak to me about circumstances beyond your control that prevent you from being in class. Late Arrivals : Arriving late to class is a disruption, so please be on time. If you arrive after I have recorded attendance, you will be marked absent. If you would like to be marked present, it is your responsibility to communicate with me in person immediately at the conclusion of the same class and I will replace the absence with a tardy. Two tardies = one absence. Please do not ask me to try to remember your attendance in class a day or two later – I may or may not be able to do so. Please speak to me about circumstances beyond your control that prevent you from being on time to class. Early Departures : Leaving early from class is a disruption, so please remain in class until its conclusion. If you leave before the conclusion of class and have not communicated to me a circumstance beyond your control that prevents you from staying the whole time, you will be marked as having an early departure. Two early departures = one absence. Course Materials: Materials for this course are located on the Blackboard website for the Geol 101 Page 2 Course Materials: Materials for this course are located on the Blackboard website for the course. You will need to log in to Blackboard using your UNC Onyen and Onyen password to access the website. Each lesson (see ―Lesson Schedule‖ below) has a folder in Blackboard with course material appropriate to each lesson, including study guides and useful tutorials and websites. Some lessons will have exercises or a quiz. To access the materials, click on the ―Assignments‖ tab in Blackboard, and scroll down until you find the appropriate lesson folder. Homework Assignments: There are three types of homework assignments in this class: 1) Reading the textbook and taking notes; 2) completing questions I assigned from the study guides; and 3) completing online Blackboard quizzes and exercises (discussed below). Reading the textbook and completing study guide questions are not assignments that have to be turned in but they are essential for your success in the class. When conducting lecture, I will assume that you are reading your textbook and have reviewed the subject chapter before you come to class (Lesson Schedule below). I also expect you to use the textbook to gain a more thorough understanding of the material after we have covered it. I often assign questions from the study guide as homework, due the next lecture period. I do not collect these questions, but I will assume you have completed them. You have the opportunity to ask me about these questions at the beginning of the next lecture, but I will not lecture on material I assigned as homework. If there are no questions about the assigned material, I will assume that you completed the material successfully and that we can move on with new material. Online Quizzes and Exercises: The quizzes and exercises are located in the Blackboard lesson folders. The quizzes were designed as formative learning tools to check your understanding of the topics addressed in the lessons. You can use your notes but you cannot collaborate with others on the quizzes. The questions will be multiple choice and are randomly generated from a question pool. You will have the option of taking these quizzes as many times as you would like, but the questions will be different each time a quiz is taken. You will be able to see the questions you answered incorrectly, but will not be given the answers until the quiz deadline has passed. Because the quizzes are timed and generated from the question pool, it is in your best interest to complete the Study Guide questions before you take the quizzes— you will receive a higher score and will need fewer attempts to be successful by completing these questions first. I will set- up the quizzes to record your highest grade. If you exceed the time limit or do not submit a quiz once you open it, you will see a ―!‖ or a symbol showing a pencil and paper in your grade book until I remove that attempt. I will remove all attempts that exceed the time limit. Note that you can always go back and look at your quiz answers by going to ―Tools‖ and ―My Grades‖ and clicking on the grade for the quiz – it will show you all of your attempts and the grades associated with these attempts. Exercises and investigations are also located in the Blackboard folders. You have unlimited time and can take attempt them as many times as you would like, as long as you complete them before the deadline. Due dates: All online assignments (including quizzes) will be due at 11:50 pm on Thursdays. You may submit assignments early, but if you miss a quiz it will disappear from your Blackboard lesson folder and you will receive a zero. Assignments in this course cannot be made up, nor can they be extended. If you do not submit an assignment when it is due, you will receive a zero for that assignment. Start your work early. I am available to answer your questions in class, after class or by appointment and will check my e- mail daily Monday through Friday. If you wait until the last minute and encounter a problem, you may not be able to complete assignments before they are due. Grace period: Because students occasionally have a problem submitting online work on time due to sickness, work, or a computer glitch, an automatic 24- hour grace period for assignments, including quizzes, is provided to all students. Please note that if you have a problem after 1 pm on Fridays, I will likely not be able to answer your questions or help you with a computer glitch. If you wait until the last minute and have a problem with a quiz or assignment, you will receive a zero. Exams: The mid- term and final exams are in- class exams and are closed book and closed notes. The mid- term and final will both be 90 minutes long and will consist of 75 multiple- choice questions. If you miss an exam, you will receive a zero for that exam. A great way to prepare for your exams is to print a clean copy of the Study Guide for each lesson the exam will cover and try to answer the Study Guide questions without referring to your notes. This is an excellent way to see what you know and what you do not know. Then, focus on studying the material you cannot readily answer on your own. Make -up exams: Exams cannot be made up except for extraordinary circumstances such as military duty, university business, hospitalization, or death in the immediate family (spouse, child, parent, primary caregiver, siblings). Prior or immediate notification of the absence is Geol 101 Page 3 child, parent, primary caregiver, siblings). Prior or immediate notification of the absence is required, as is documentation of the reason. If a make- up exam is approved, the make- up exam date must be taken within one week of the original exam date. The make- up exam will consist of essay questions, and you will need to make special arrangements with me to take the exam. Course Mechanics I will teach the lecture using inquiry- based learning methods, where we will be answering questions from the study guides during class. Typically I will give you an introduction to a topic, then we will proceed to answer the questions together through Power Point, animations and videos. You will also break into groups were you will answer the questions on your own. Some questions are simple definitions, so I will ask you to do these for homework. Sometimes we don’t get through all of the material in lecture, and I will ask you to finish up this material at home. It is important to print-out the appropriate study guides and investigations prior to coming to class so that you can work on activities together in a group and can answer the questions in class. The more work you do in class, the less work you will have to do on your own outside of class. Sample Homework Schedule: Here is some advice about how to best use your out- of- class study time. Read and take notes on assigned chapter pages in textbook. Try to answer the study guide questions as you g o. Review answers to study guide questions discussed in class. All study guide questions are posted in “Assignments” on Blackboard. Check “Assignments” on Blackboard for homework updates and view helpful animations and websites. Complete any study guide questions assigned in class as homework. Review your notes, study guides and quizzes in preparation for tests. Tests will be based on the material included in the study guides. Classroom Expectations : Respect and be kind by remaining silent and listening when someone else is speaking, staying alert, engaging in classroom activities, putting away all newspapers and other unrelated papers and work while class is in progress, putting away all food, shutting off cell phones and other electronic devices, arriving on time and staying in class until you are dismissed. All of these behaviors minimize distractions and enhance the learning environment. Breaks: When students leave the classroom to use the restroom, buy a coke, etc. and then return to class, it disrupts instruction - twice. Please be kind and take care of your needs before you come to class. There will usually be a time mid- class when students are completing an in- class assignment when you can to go to the bathroom if necessary. Laptops: Laptops used to work on the material being discussed in lecture are welcome in this class – if I were taking this class I would bring one myself. However, you may not use your laptop to check your email, browse the internet, check your grade, do work in another class, take an online quiz, or do class work other than what is being discussed in lecture because these activities cause distractions. You will be asked to put away your laptop if you engage in these prohibited laptop activities, and will be prohibited from using your laptop in class if I have to ask you more than once to put it away. Other Electronic Devices: These are not welcome in class. All cell phones, media players, etc. must be turned off and put away when entering lecture. Lesson Schedule *This schedule is tentative and the instructor reserves the right to amend it at any time. If there are updates, they will be posted under ―Course Schedule‖ on Blackboard. Lesson Dates/Due Dates Lesson May 10 Introduction May 11 Topics and Required Reading Lesson 1 Read the syllabus. Review the Blackboard site. Obtain and familiarize yourself with the textbook. Introduction to Geol 101 Page 4 Geology and Formation of Earth Chapters 1 and 2; Chapter Sections 5.4, 9.9 and 19.1. May 12 and Lesson 2 13 Plate Tectonics Chapter 3; Chapter Sections 10.2 – 10.6; Section 10.10; Section 11.7 May 16 Lesson 3 Minerals and Rocks Chapter 4; Chapter Sections 1.5-1.6 May 17 and Lesson 4 18 Igneous Rocks and Magma Chapter 5 May 19 and Lesson 5 20 Volcanoes Chapter 6 May 19 11:50 PM Blackboard Quizzes: Lessons 1 and 2 (50 points – Lesson 2 folder) Investigation 3 (20 Points – Lesson 2 folder) Lessons 3 and 4 (60 Points – Lesson 4 folder) Investigation 5 (20 Points – Lesson 4 folder) May 23 and Lesson 6 24 Weathering, Soil, and Mass Wasting Chapter 15 May 25 and Lesson 7 26 Sedimentary Rocks Chapter 7 May 26 11:50 PM Blackboard Quizzes: Lesson 5 (30 Points – Lesson 5 folder) Lesson 6 Including Investigation 15 (40 Points - Lesson 6 folder) Lesson 7 Including Investigation 7 (40 Points – Lesson 7 folder) May 27 Mid-Term Exam (250 Points) 75 multiple choice questions covering Lessons 1-7. Please bring a Scantron sheet, sharpened #2 pencils and erasers and a calculator that is not a cell phone to the exam. May 30 Memorial Day Holiday May 31 and Lesson 8 June 1 Deformation and Metamorphism Chapter Section 11.2; Chapter 8 June 2 Lesson 9 Geologic Time Chapter 9 June 2 11:50 PM Blackboard Quizzes Due: Lessons 8 (40 Points – Lesson 8 folder) Lesson 9, Including Investigation 9 (40 Points – Lesson 9 folder) June 3 and 6 Lesson 10 Earthquakes and Earth's Interior Chapter 12 June 7 Lesson 11 Rivers and Flooding Chapter 16 June 8 and 9 Lesson 12 Ground Water Chapter 17 June 9 11:50 PM Blackboard Quizzes Due: Virtual Earthquake Exercise (40 Points – Lesson 10 folder) Quiz on Lesson 10, including Investigation 12 (40 Points – Lesson 10 folder) Quiz on Lesson 11, including Investigation 16 (40 Points – Lesson 11 folder) Geol 101 Page 5 Lesson 11 folder) Quiz on Lesson 12, including Investigation 17 (40 Points Lesson 12 folder) June 10 Lesson 13 Shorelines, Glaciers, a nd Sea -Level Change Chapter 14 June 13 Final Exam (250 points) 11:30 AM – 2:30 PM, 75 multiple-choice questions covering Lessons 8 through 13. 05 Mitchell Please bring a Scantron sheet, sharpened #2 pencils and erasers and a calculator that is not a cell phone to the exam. Optional Cumulative Final If you would like to improve your Mid-Term Exam score, you may take an optional final that will include 50 questions. At least half of the questions will be similar to the questions on the Mid-Term. If y our score on the Optional Final is better than your Mid-Term exam score, I will replace your Mid-Term exam score with the s core for your Optional Final. If you plan to take the Optional Final, please bring an additional s cantron. Pasted from <file:///C:\Users\Brandon\AppData\Local\Temp\h33xadd1.tmp\Summer%202011.doc> Geol 101 Page 6 Introduction Tuesday, May 10, 2011 11:46 AM Geol 101 Page 7 Geol 101 Page 8 Geol 101 Page 9 Geol 101 Page 10 Geol 101 Page 11 L1- Introduction Wednesday, May 11, 2011 11:51 AM Geol 101 Page 12 the material that formed the solar system is Nebula NEBULA • a region or cloud of interstellar dust and gas appearing variously as a hazy bright or dark patch Proto Sun- is the sun before the sun what happened was nuclear fusion that caused the sun to become what it is today . Fission- splitting atoms apart Fusion- where two atoms fuse together and that’s how we get the heavier elements on earth Fusion >Fission Geol 101 Page 13 How did the planets form Space trash began to clump together through accretion Accretion- when particles come together The big whack theory things from the mantle of the earth merged together to create the moon Bolide=impacter (hit the earth) Moon has the same chemistry as the earths mantle the reason the core is made of iron is because a stony iron meteorite hit the earth and part of it was deflected off to become the moon. Geol 101 Page 14 the outer core is liquid and the inner core is solid rock of iron magma is liquid rock from the mantle the earth was first homogonous Geol 101 Page 15 Geol 101 Page 16 Geol 101 Page 17 Geol 101 Page 18 Guide W ednesday, May 11, 2011 12:19 PM GE0L 101 Lesson 1 Study Guide Chapters 1, 2 and 19 —Introduction and Formation of Earth The Nature of Geology 1. The book talks about how geology can help us find copper and iron. Using the logic used in your book, how do you think geologists go about finding oil? 2. Scientific Method a. Be able to summarize the steps involved in the scientific method. b. Describe how data differs from interpretations and give one example. c. What is a hypothesis? d. How does a hypothesis become an established theory? e. Why are scientific explanations never proven to be true? 1. Calculations a. Calculate the following. Use the correct units: The number of miles that are in 2,900 KM. 2900/1.6=1812.5 The area of a football field 100 yards long and 53 yards wide. 100*53=5,300 The volume of water in a pool that is 25 yards long, 50 yards wide and 5 feet deep. 25*50*5=6,250 b. What is the difference between the following? Elevation: Relief: Depth: c. What is the difference between weight and density? d. How do you calculate density? Mass/Volume e. Distance = Velocity x Time. So, how far can you travel in one hour if you go 60 miles per hour? 60*1=60 f. Solve this problem: The earth’s interior is composed of three main concentric zones (or four if you separate the inner and outer core): Crust: about 40 KM thick Mantle: 2900 KM thick Core (outer and inner): 3470 KM thick A) Assuming you can walk 10 miles a day, how many days would it take you to walk to the crust- mantle boundary if you started at the surface? (Hint: 1 mile = 1.6 KM) B) How many more days would it take to get to the center of the earth? Geol 101 Page 19 C) How many months would the whole trek take? Origin of the Solar System, Planets and Moon – 19.1 1. Go to the Lesson 1 ―Suggested Websites‖ in Blackboard to view a small tutorial on the birth of the universe, galaxies, our solar system, and predictions about the future of the universe. 2. Formation of Solar System: Go to the ―Formation of the Solar System‖ animation in the ―Suggested Websites‖ in your Lesson 1 folder to view an Exploring Earth website entitled ―Observe an animation showing the origin of the solar system‖. Then answer the following questions: a. What material formed earth’s solar system? What do we call this material? the sun and planets condensed from a nebula, a shapeless cloud of gas and dust b. How did the sun form? The remnants of previous stars and cosmic dust all of which had a beginning in what is called the big bang. the sun continued to attract more material and became massive enough to begin atomic fusion and to emit protons and electrons in a solar wind. the wind reached the inner planets blowing away hydrogen helium and other light elements leaving only heavy materials c. How did the planets form? particles of dust clung together to form small chunks and then larger and larger pieces eventually ending up as planets 3. Formation of Moon: Go to ―The Big Wack‖ website in the Lesson 1 ―Suggested Websites‖ folder in Blackboard to understand how the moon formed. Then answer the following questions: Summarize the impact theory (―Big Whack‖ theory) of the moon’s formation. during the early stages of formation the earth is thought to have collided with another large object that was not quite a planet ripping away part of the earth forming our Moon According to the theory, how did earth’s iron core form? According to the theory, what is the moon made of? Age (Ch.9.9), and Composition of Earth – Ch.1.3 1. What is the age of the earth, and what evidence supports this age? (Ch.9.9) (Hint: There are 3 lines of evidence) Earth: 4.55 Billion years old • Moon rocks= 4.5 Billion • Meteorites = 4.53 leftovers of the formation of the solar system • Dated minerals= in rocks from Australia and Canada oldest mineral is 4.4 billion years old the mineral that came was from crystallization. 2. Earth became differentiated after it formed. View the figure below and answer the following questions: Which of the four ―worlds‖ above are most differentiated and which are least differentiated? Earth is differentiated like the world in ―A‖. In general, how does the density of the earth change with depth from Geol 101 Page 20 Earth is differentiated like the world in ―A‖. In general, how does the density of the earth change with depth from the surface to the core? Explain how earth became differentiated (Hint: See differentiation animation at the following website: 3. Draw the 4 layers of the earth (crust, mantle, outer core and inner core) and then compare the layers in the table below: Layer Phase (ie -solid,molten) Description (composition, thickness) Crust Solid Granite(composition) M antle Solid Basalt, (Mineral Olivine) Outer Core Liquid Iron Inner Core Solid Iron and Nickel 4. The diagram below shows the more detailed layers of the earth. Study the diagram and answer the questions below Summarize the differences in density and thickness between continental crust and oceanic crust. • thickness is higher inland an in the ocean on average between 30KM - 50KM(Continental) and the ocean (5- 7KM) • Continental crust is Granite and Oceanic is Basalt • Basalt is more dense than Granite What two earth layers combine to form the lithosphere ? Crust and the top of the Mantle is 100KM into the Earth What is the difference between the lithosphere and asthenosphere . Asthenosphere is below the lithosphere and is not totally solid, consists of parts of molten rock and is made of a silly putty like material. Asthenosphere is fairly weak and acts like a plastic. extends about 660 km located into the upper mantle. Compare the asthenosphere to the mantle Mantle is thicker, 5. Explain why continental crust has higher elevations than oceanic crust using the principle of isostacy. The following tutorial may help you: Isostacy- buoyancy differences in thickness related to age and differences in density Ocean crust sinks into mantle because it is more dense Isostactic Equilibrium • when there is no sinking or rising. How do Temperature and Pressure Vary Inside Earth? – Ch.5.4 6. Describe the events that made the early Earth hot. Because of radioactive decay at the core • i.e. Uranium □ reasons why the earth continues to be hot. 7. What causes earth’s internal heat source? radioactive decay at the center of the earth Geol 101 Page 21 radioactive decay at the center of the earth 8. How do earth’s pressures and temperatures change with depth? Geothermal Gradient 9. Describe the geothermal gradient, and give the range of geothermal gradients that exist in the crust. as you go deeper the temperature increases generally 10. Compare the average temperature of the surface of the earth to the estimated temperature of the core. 30c/km on average in crust and center is 5000c/km 11. Summarize three ways the heat is transferred from a warmer mass to a cooler one. Give one example of how heat transfer (conduction, convection or radiant) occurs in earth. • Conduction- when magma comes in contact with rock heating it • Convection- Transfer of heat by movement, when particles heat up move and rise then cool off and become more dense then sink like a pot of boiling water. this generally occurs in the mantle • Radiant- Sun sends radiation (UV) (inferred) by in direct means ***COLD THINGS ARE MORED DENSE THAN HOT THINGS!!*** Pasted from <file:///C:\Users\Brandon\AppData\Local\Temp\j3gm0x6t.tmp\Lesson%201%20Study%20Guide%20(Ch.1,%202%20and%2019.1-Intro%20and% 20Formation%20of%20Earth).doc> Geol 101 Page 22 Lesson 2 Thursday, May 12, 2011 11:28 AM Theory-is a assumption based on evidence has been proven true through many test Plate Tectonic is how we connect the geographic world brought about in the 1960s Geol 101 Page 23 Geol 101 Page 24 Magnetometers Bathymetry - is the depth of the ocean floor better picture after WWII Geol 101 Page 25 The tectonic plates don’t only include continents but they also include ocean plates. They each move as one Geol 101 Page 26 Geol 101 Page 27 Geol 101 Page 28 Geol 101 Page 29 Geol 101 Page 30 Geol 101 Page 31 Geol 101 Page 32 Geol 101 Page 33 Geol 101 Page 34 Geol 101 Page 35 Geol 101 Page 36 Geol 101 Page 37 Geol 101 Page 38 Geol 101 Page 39 Geol 101 Page 40 Guide Thursday, May 12, 2011 11:25 AM GEOL 101 Lesson 2 Study Guide Chapter 3—Plate Tectonics The following link has an excellent tutorial on plate tectonics and shows animations: You can answer the questions below using this tutorial and/or the textbook. Continental Drift Theory (Section 2.5) 1. Describe three lines of evidence that supported Alfred Wegener’s ideas that the continents drifted apart. Evidence Description Geography the continents were shaped in a way in which they looked like they could be placed together believed that their was a continent that was once together and it was called Pangaea Fossils identical fossils for the identical time period on different continents. • Mesosaurus Climate Paleoclimate, and deposits of glacial deposits were left near Africa. There is coal in Antarctica Rock Matching rocks and mountain belts across the Atlantic 1. Why was Wegener’s hypothesis not accepted at first? Alfred Wegener said the way the continents moved was that they plowed through the ocean crust. • was not a way that they moved = Hypothesis was thrown out Evidence for Plate Tectonics (Sections 3.2 – 3.3, Section 10.4) 3. On a relief map of the world, be able to identify the following topographic and bathymetric features: a. mountainous and flat areas on land 1) Mountains are brown and white on land a) have a pattern that in which they are distributed i) linear or arched shaped b. mid- ocean ridges in the ocean 1) Places in the ocean that are high a) separated by fracture zones c. fracture zones, sea mounts and island chains in the ocean 1) Sea mounts- Underwater Volcanoes ( look in the pacific ocean) a) you get a line of mountains around Hawaii 2) Island Chains a) Lucian islands d. trenches in the ocean 1) Deepest places in the oceans a) deepest places on earth can go 7km deep 4. Describe how the distribution of earthquakes and volcanoes relates to Earth’s topographic and bathymetric features. a. Volcanoes and Earthquakes are usually located along the mid ocean ridge b. Anywhere you have mountains you have earthquakes 1) next to plate boundaries a) 5. How do plate boundaries relate to the features noted above? a. physiographic things on earth are clues to where plate boundaries are located 1) Trenches, Mountains, Island chains, topography, Bathymetry Seafloor Spreading and Magnetic Anomalies (Sections 10.4, 10.2) 6. How does ocean crust change with increasing distance from a mid- ocean ridge? a. as the crust moves away from the ridge the deeper the ocean crust is. Sea Level Lithospheric Plates Ridge Ocean Crust/lithosphere gets deep with distance from ridge . Deepest parts are away from the ridges and near trenches Density of ocean lithosphere increases with distance from ridge Geol 101 Page 41 Lithospheric Plates Ridge Deepest parts are away from the ridges and near trenches Density of ocean lithosphere increases with distance from ridge 7. How does the theory of seafloor spreading explain this change? a. is when new seafloor or ocean crust is being made at the ridges by new magma coming up to the earth b. becomes more dense because it cools and sinks making it deeper. 8. Be able to predict the relative ages (older, younger) of the oceanic crust on a map of an ocean showing an ocean ridge. a. Oldest is 180 Billion years old and they get older as you move from red to blue and as you move away from the ridges of the ocean 9. Explain how Earth’s magnetic field is generated. Created by the earths iron magnetic core which is caused when the free electrons move that creates a electrical field 10. What is a magnetic anomaly (magnetic reversal)? Patterns that magnetometers picked up while looking for iron submarines. Magnetic Anomaly is Expected 0 + Anomaly Sea Level White is positive an d red is negative. Ridge 11. Explain how magnetic anomalies support the theory of seafloor spreading. as new magma comes up from the earth the new rock will take on the magnetic pull of the earth Normal Polarity = Magnetic field today Reversed Polarity = Reversed from today alignment of magma that comes up along the ridges and erupts at the same time and moves away 12. Describe ―plates‖— what are they, and what part of Earth makes up the plates? Plate Boundaries (Sections 3.3 – 3.5) Sketch and e xplain how the following tectonic boundaries form, and give examples of each: 13. Divergent Boundaries a. Spreading Centers (Mid- ocean ridges) b. Continental Rift Zones 14. Convergent Boundaries a. Ocean- Ocean Subduction b. Ocean- Continent Subduction c. Continental Collision 15. Transform Boundaries a. Transform boundary at a spreading center Geol 101 Page 42 What is a plate? these are lithospheric plates which means the crust and parts of the mantle. the reason they are broken up is because plates actually ride on the weak Asthenosphere a. Transform boundary at a spreading center b. Transform boundary on land 16. Plate Movement a. Summarize the driving forces of plate tectonics. b. What are the typical rates of relative plate motion between plates? Ocean Hot Spots and Island Arcs (Sections 10.5 – 10.6) 17. What is a hot spot and how does it form? Draw the process that forms a hot spot. is a place were hot mantle material are rising from deep within the mantle. Developed by a plum of magma □ lithospheric plate moves magma is injected into lithosphere and land is lifted and makes volcanic islands 18. How and where do linear island chains and s eamounts form? Seamounts form by hotspots they are old volcanoes no longer breaking the surface 19. Calculate the rate of plate movement of the Hawaiian Island chain if the Island of Kauai formed 5.1 million years ago and was transported 600 KM to the northwest. Give your answer in cm/year. (Hint: There are 100,000 cm in a kilometer.) 100000cm*600km=60000000cm 60/5.1=11.7647cm/yr 20. What is an island arc and how does it form? Draw the process that forms an island arc. Islands arcs are arc shaped chains of volcanoes □ caused by subduction and earth is a sphere which causes the curved shape 21. Both ocean hot spots and island arcs form chains of volcanoes in the ocean. Explain the differences between the two and how they form. Island Arcs • Arc Shaped • Have a trench next to them • Near a Subduction zone • More dangerous than Hot Spot Hot Spots • straight lined • no trench • no subduction zone Ocean vs Continental Hot Spots (Section 11.7) Calderas 22. Compare the physiographic features of oceanic hot spots and continental hot spots . Melting Continental Crust makes explosive e ruptions Continental Crust magma 23. Compare the processes that form ocean hot spots and continental hot spots. 24. Compare the hot spots formed at the following places, noting the locations that have calderas, triple junctions, failed rifts : a. Yellowstone National Park □ formed from a hot spot □ Caldera is a huge opening caused by huge explosion □ explosive because of magma is erupting in a continental hotspot and the clue is large calderas □ erupts regularly because of regular ground water flow Geol 101 Page 43 □ erupts regularly because of regular ground water flow b. East Africa • Started as a hot spot and morphed in continental divergent then an ocean boundary • Triple junction hot spot cracked ocean crust and a divergent boundary started in 3 places • Divergence started that has caused the separation of the red sea has become failed rift high plateaus and low valleys 25. Describe the evolution of a continental hot spot to a triple junction and finally a divergent boundary creating an ocean basin. Passive vs Active Continental Margins (Section 10.10) 26. What is the difference between an active margin and a passive margin? 27. Compare the physiographic features you would expect to find on passive continental margins with those you find on active continental margins. Continent B Continent A Geol 101 Page 44 Thursday, May 12, 2011 10:23 PM Investigation 3.10 (page 70 in your book) To complete this worksheet, see the instructions in the textbook (Chapter 3 Investigation). Table 1. Plate Boundaries of an Unknown Ocean and Continents This perspective view shows two continents, labeled A and B, separated by an ocean. Use the topography to identify possible plate boundaries and to propose whether each boundary is divergent , convergent , or t ransform . Use colored pencils or pens to mark the location and type of each plate boundary on the figure below. Use the following colors: divergent = black; convergent = red; transform = green or blue. For transform boundaries, mark only transform faults (where motion is still occurring), not fracture zones (where it is not). ▲ ▲ Passive Margin ▲ ▲ ▲ + Hotspot ▲▲ + ▲ Passive Boundary Continental Shelf ▲ ▲ Seamount Table 2. Predicting the Location of Earthquakes and Volcanoes Use your plate boundaries to mark where on the map earthquakes and volcanoes are most likely. On the figure above, do the following: Draw circles [○] at any place, on the land or on the ocean floor, where you think earthquakes are likely. Draw triangles [▲] in any place, on land or in the ocean, where you think volcanic eruptions are likely. Remember that not all volcanoes form directly on the plate boundary; some form off to one side. Also, a line of islands and s eamounts (mountains that are beneath the sea) could mark the track of a hot spot and may not be on a plate boundary. + Table 3. Determining a Safe Place to Live Determine a relatively safe place to build one city on each continent. Show each location with a plus sign [+] on the map. In the space below, explain your reasons for choosing these as the safest sites. Reasons for location of city on Continent A: Reasons for location of city on Continent B: Geol 101 Page 45 Table 4. Showing the Plate Boundaries in Cross Section On the figure below, draw a simple cross section of your plates in the subsurface. Use other figures in this chapter as a guide to the thicknesses of the crust and lithosphere and to the geometries typical for each type of plate boundary. Some features are not located along the front edge of the figure and so cannot be shown on the cross section. Draw the geometries of the plates at depth for any spreading center or subduction zone. Show the variations in thickness of the crust and variations in thickness of the lithosphere. Draw arrows to indicate which way the plates are moving relative to each other. Show where melting is occurring at depth to form volcanoes on the surface. Continent A Continent Melting Pasted from <file:///C:\Users \Brandon\AppData \Local\Temp\r3zs6upv.tmp\Lesson%202%20Study%20Guide%20(Chapter%203).doc > lithosphere asthenosphere Geol 101 Page 46 Lesson 3 Monday, May 16, 2011 11:39 AM Geol 101 Page 47 Geol 101 Page 48 Geol 101 Page 49 Geol 101 Page 50 Geol 101 Page 51 Geol 101 Page 52 Geol 101 Page 53 Geol 101 Page 54 Geol 101 Page 55 Geol 101 Page 56 Geol 101 Page 57 Geol 101 Page 58 Geol 101 Page 59 Geol 101 Page 60 Geol 101 Page 61 g Geol 101 Page 62 Geol 101 Page 63 Geol 101 Page 64 Geol 101 Page 65 Geol 101 Page 66 Geol 101 Page 67 Geol 101 Page 68 Geol 101 Page 69 Geol 101 Page 70 Geol 101 Page 71 Geol 101 Page 72 Geol 101 Page 73 Geol 101 Page 74 Geol 101 Page 75 Geol 101 Page 76 Geol 101 Page 77 Geol 101 Page 78 Geol 101 Page 79 Geol 101 Page 80 Guide Sunday, May 15, 2011 7:22 PM GEOL 101 Lesson 3 Chapter 4—Minerals and Rocks In addition to your book, please view the tutorials provided in the ―Suggested Websites‖ for this lesson on Blackboard. They are excellent resources for learning about minerals and rocks. Minerals, Rocks and Elements (Sections 4.1 and 4.2) 1. Name the five characteristics of a mineral and briefly describe them: Property Description Natural Made naturally by the earth Inorganic nothing that was involved in the creation of rock Ordered internal Structure the way in which it is made structurally Chemical Composition Same chemical composition throughout, no matter where you find the mineral Solid 2. Is ice a mineral? Why or why not? 3. How are minerals and elements related? How about minerals and rocks? Mineral Chemistry and Bonding (Sections 4.11 – 4.13) If your chemistry is a bit rusty, see the mineral animations noted in the link above and fill - in the table below: 4. Compare and note the difference between the following: Proton positive charge located in the nucleus number is equal to the atomic number Neutron neutral charge located in the nucleus Electron Periodic table arranged in rows which e qual to the number of shells the atom has. negatively charged and usually equal to the number of protons Atom Atoms are arranged in the columns by the number a valence electrons. Electron Shell Valence = outer shells Molecule Octet rule 2-8-8 5. Using Sections 4.6 and 4.9, define the following a. Atomic Number: i. How many protons does calcium (Ca) have in its nucleus? i) 20 ii. How many protons does oxygen (O) have in its nucleus? i) 8 b. Silicate: c. Carbonate: d. Oxides: e. Halides: f. Sulfates: g. Sulfides: h. Native minerals: 6. Element abundances: Use Section 4.10 to define the following: a. Three most abundant elements in e arth’s crust: b. Four most abundant elements in entire earth: c. Considering the differences in the composition of earth’s layers, e xplain why a and b are different. 7. Valence Elections The Periodic Table shows how many electron shells each electron has, and how many electrons are in the outermost shell. The outermost shell is important b ecause the number of electrons in the outermost shell (determines how the element will bond. Refer to Section 4.11 and fill- out the following table (the first one is done for you). When you draw the atom, note that only two electrons can fit in the inner shell, and for smaller atoms, eight electrons can fill each of the next several shells . The first one is done for you. Geol 101 Page 81 inner shell, and for smaller atoms, eight electrons can fill each of the next several shells . The first one is done for you. Element Lithium (Li) # of Protons # of Shells Electrons in Outer Shell 3 1 3 2 2 5 4 Magnesiu m (Mg) 2 Drawing 1 12 Nitrogen (N) 7 Potassium (K) 19 Bonding: Minerals will tend to gain or lose electrons or share electrons to achieve full outer shells (eight in most cases), depending on their electronegativity. 7. Compare ions , cations and anions and give examples. Ion- when an atom gains or loses an electron Cations- Positive atom because loses electron Anions- Negative atom that gains an electron Gain or lose to fill the outer shell 8. What is e lectronegativity? Compare the electronegativity of the left and right sides of the periodic table. the measure of the ability to attract electrons The more able an atom is able to attract electrons the more electronegative it is Lower the energy required to build outer shell The farther you move right the more electronegative 9. Using the periodic table in section 4.12 of your textbook, predict what will happen to the following atoms based on the numbe r of electrons in their outer shell. The first one is done for you. Atom # of valence electrons Will they gain or lose these? Name of ion and charge K 1 lose Potassium cation K+ Cl 7 gain Chlorine anion Cl- O 6 Gain Oxygen Anion Al 3 Lose Aluminum Cation Al3+ O2- 10. Describe the different types of bonds that form minerals — note what happens to the outer shell electrons in each type of bonding. Give an example of each type of bonding. Bond Covalent Description • when two atoms share electrons in order to fill its outer shell • Very Strong bonds • Covalent Sharing Example Oxygen sharing electrons • Molecule • Diamond • Bonds where an electron is received or given up by an atom • Electronic Attraction between positive and negative ions. • Ionic Transfer Sodium and Chlorine • NaCl - Salt (halite) • Common in metals, Freely mobile electrons shared between all the ions of the structure minerals with metallic bonds are goo electrical conductors • Metallic Intermolecular • Weak bonds that attract like sheets • No transfer or Share but a attraction because of the arrangement of the molecule like static electricity Hydrogen Bonds • Bonds between water molecules • Weak bond that involve hydrogen • hydrogen is polarized ○ because of the charges on different atoms Ionic Geol 101 Page 82 Breaking and Forming Mineral Bonds: Dissolution and Precipitation View the animation called ―Animation of Dissolving NaCl‖ and ―Animation of a Precipitation Reaction‖ in your Blackboard folde r to see how crystals can grow from molecules, then answer the following questions: 11. Describe/draw the polarity of the water molecule and explain how this helps it to dissolve a mineral. oxygen H+ H+ 12. Describe how halite (salt) dissolves in water. The polarity of the water molecule, and water is a solvent which is a substance that likes to dissolve Important because it is one way in which minerals form 13. Describe how a mineral can precipitate (grow) in water. two ions come together that are oppositely charged come together □ clusters are formed when they get heavy they sink □ Precipitate is formed and that is the mineral. Physical Properties: Internal Structure, External Form (Sections 4.3 –4.5) Crystal Shape (Crystal Habit): 14. Describe how ionic radius controls the internal structure (shape) of the crystal lattice and therefore crystal shape. 15. How is crystal shape affected by the environment in which it grows? 16. Sketch the three common arrangements of atoms in crystals Internal structure affects the crystal shape of the mineral, inner shapes the outer Cubic Tetrahedron Octahedron Cleavage, Hardness and Streak: 17. What causes cleavage in minerals? tendency of a mineral to break along a preferred plain of weakness 18. Why would a mineral fracture , but not cleave? 19. Fill- in the following table, associating cleavage directions with crystal shape: Number of Cleavage Directions Crystal Shape Example of Mineral with this cleavage One direction Two Perpendicular Directions Two Non- Perpendicular Directions Three Perpendicular Directions Cube Halite Three non- perpendicular directions 20. What is M oh’s hardness scale, and what does it represent? 21. Hardness is controlled by mineral bonding. Usually the harder the mineral, the stronger the bonds. Given this information, predict the types of bonding that probably occur in the hardest, softest and middle minerals on the scale. 22. What is mineral s treak? Silicate Minerals (Sections 4.7 and 4.8) 23. Explain why silicates are the most abundant minerals in the crust. 24. What types of bonds form silicates? 25. Complete the following table, showing the differences between the five different silicate mineral groups. Type of Silicate Independent (Isolated) Sketch Geol 101 Page 83 Examples Independent (Isolated) Olivine Single Chain Pyroxene Double Chain Amphibole Sheets Muscovite Frameworks Quartz How do Rocks Form? (Sections 1.5 and 1.6) 26. Remember that minerals combine to form rocks. Distinguish the processes that formed the three main rock types: Where in/on Earth do Rock Type Sedimentary Process they form? Igneous Metamorphic 27. Sketch a simple version of the rock cycle, labeling and explaining in your own words the key processes. Pasted from <file:///C:\Users\Brandon\AppData \Local\Temp\7ve93bk2.tmp\Lesson%203%20Study%20Guide%20(Chapter%204).doc > Geol 101 Page 84 Lesson 4 Tuesday, May 17, 2011 10:11 AM Geol 101 Page 85 Geol 101 Page 86 Geol 101 Page 87 Geol 101 Page 88 Geol 101 Page 89 Geol 101 Page 90 Geol 101 Page 91 Geol 101 Page 92 Geol 101 Page 93 Geol 101 Page 94 Geol 101 Page 95 Geol 101 Page 96 Geol 101 Page 97 Geol 101 Page 98 Geol 101 Page 99 Geol 101 Page 100 h Geol 101 Page 101 Geol 101 Page 102 Geol 101 Page 103 Geol 101 Page 104 Geol 101 Page 105 Geol 101 Page 106 Geol 101 Page 107 Geol 101 Page 108 Geol 101 Page 109 Geol 101 Page 110 Geol 101 Page 111 Geol 101 Page 112 Geol 101 Page 113 Geol 101 Page 114 Guide Tuesday, May 17, 2011 10:12 AM GEOL 101 Lesson 4 Study Guide Chapter 5—Igneous Rocks and Magma In addition to your textbook, please view the tutorials on igneous rocks and magma provided in the ―Suggested Websites‖ folde r for Lesson 4 on Blackboard. Igneous (Magmatic) Rock Classification (Section 5.1 – 5.3) I. Texture Crystallization when a liquid starts to form into a solid 1. What is the difference between magma and lava? Magma- exist between 1200- 600C°= Melted rock onto the ground is magma • Rock- > Crystallized at 900° and below Magma =melt ◊ Magma= melt + Crystals ► Rock Lava= Liquid which magma becomes lava 2. What is the difference in texture (grain size) between intrusive and e xtrusive rocks? II. slow= large crystals rapid= is small crystals 1) Extrusive Rocks a) Rocks (lava) that cool on the surface get rapid cooling and have fine grains i) Cool quickly on the surface so they have small crystals • cant see them with the naked eye • Small Crystals = aphonitic texture 2) Intrusive Rocks a) Rocks that crystallize under the ground from magma i) cool slowly and have large crystals 1. can see them with the naked eye 2. Phaneritic texture 3. Can be called plutonic 3. Explain how the following igneous textures form (the first one has been done for you: Texture What is it? How/where does it form? Fine grained Very small crystals that you can’t see When lava cools quickly at low temperatures on Earth’s surface with your naked eye. (extrusive rock). (aphanitic) Coarse grained (phaneritic) Pegmatite Rock that has very large crystals Intrusive that formed underground with water present in magma chamber took the most time to form Porphyritic (rhomb porphyry) Rocks where you can see some crystals and cant see others you cant. smaller crystals (Chocolate Chip Cookies) Large x-tals (phenocrysts) Ground mass (aphanitic) started forming underground and were pushed up to the surface by eruption and the crystals were erupted on the surface and cooled very quickly. History: Fast and Slow • Is Extrusive and Intrusive Rock Volcanic glass (obsidian) Extrusive Rock with a glassy texture with no grain visible all glass because its cooled so quickly it doesn’t have time to even form crystal structures (Silica, Oxygen) get Glass Pumice (Vesicular) Scoria (Vesicular) Volcanic Breccia Tuff Geol 101 Page 115 Welded Tuff II. Composition Silicate • What the rock is made of: Minerals that make up the rock a common rock-forming mineral Indicated by Color belonging to a group formed ◊ Felsic Rocks from silicon and oxygen ► Quartz, Potassium- Feldspar -> Silicates combined with various elements ► Light in color and classified by their crystalline Pink, Light gray, White structures ◊ Intermediate Rocks ► Intermediate in color ► has Plagioclase -> Gray, White, and Black ◊ Mafic ► Dark in color Olivine and pyroxene Black Dark Gray ◊ Ultramafic ► Dark in color Green or black 4. Provide the appropriate information for each composition given. When asked for silica or Fe/Mg content, use the words ―low, intermediate, high, very high‖. The first one is done for you. Property Intermediate Mafic Ultramafic Granite Diorite Gabbro Comatite (RARE) Fine Grained Rock Name Aphanetic (extrusive) Rhyolite Andesite Basalt Vesicular basalt Peridotite 2 Most Abundant Minerals Quartz and k- feldspar Plagioclase Olivine Pyroxene % Silica High – about 70% Mg, Fe Lowest Color Texture Felsic Coarse Grained Rock Name Phanaritic (Intrusive) Light Lowest MG Fe Intermediate Dark: black Dark Gray Green or Black Iron makes things Green 5. Below is a photo of an igneous rock (penny for scale). A description accompanies it. Analyze the rock (break it down into its texture and composition) to explain how it formed. The rock at left has an aphanitic groundmass with a black phenocrysts. Explain how it formed. NAME :ANDESITE Porphyry • Intrusive and Extrusive ○ started underground and finished above ground ○ Porphyritic ○ Ground mass is fine grained • Intermediate Rock 1 2 3 4 5 Aphanitic Mafic V esicular Aphanitic Aphanitic Apahnitic Light color Mafic Felsic feslic Basalt V esicular 6 phaneritic Intrusive Felsic Coarse Grained Extrusive and intrusive Intrusive Intermediate Porphyritic Geol 101 Page 116 7 Mafic Light color Mafic V esicular feslic Basalt V esicular Basalt Rhyolite Felsic V esicular Light weight Pumice Intrusive i ntrusive Felsic Intermediate Large Crystals Diorite ( pegmatite) Granite Intrusive Porphyritic IntermediateComposition Andesite Porphyry comp history Magma Formation and Composition (Sections 5.5 and 5.6) 6. Since the crust and mantle are mostly solid, magma can only form when rock melts. The following phase diagrams show different ways rocks can melt. Indicate the type of melting shown, and describe how rocks can melt this way. Melting= Breaking the bonds of solids Type of Melting Represented M elting Curve How rocks can melt this way Heating Decompression acts as a solvent that dissolves bonds Adding Water Composition of Magmas Produced by Partial vs Complete Melting 7. Compare complete melting to partial melting. Partial Melting- Melt that forms Is richer in silica than the source rock • Felsic minerals melt before mafic minerals • Produces magma that is more Felsic and has more Silica Complete Melting 8. Felsic minerals melt at lower temperatures than mafic minerals , s o when rocks partially melt, magmas produced are more felsic than the parent rock. Predict what type of magma will be generated in each part of Earth if that part of Earth partially melted Earth Layer Composition of Earth Layer Composition of magma if layer is completely melted Composition of magma if layer partially melts Continental Crust Felsic Intermediate to Felsic Felsic Oceanic Crust Mafic Mafic Intermediate Mantle Ultramafic Ultra Mafic Mafic Changes in Magma Composition Due to Crystallization, Assimilation and Magma Mixing 9. Explain how crystal settling (aka fractional crystallization) can cause magma to become more felsic during crystallization. a) Crystal Settling i) Floating and sinking crystals 1. first formed minerals that sink are the more mafic minerals First. More felsic ii) Settling is a way in which magma changes and to be more felsic iii) Mafic Minerals are dense and sink and Feslic are less dense iv) Another name is Fractional Crystallization 1. occurs due to crystal settling 2. Early formed crystals fractionate or partition from the melt First. way to get a more felsic magma from one that may not have been feslic 10. Explain how a magma of intermediate composition could be produced by the processes of magma mixing and assimilation. i) Magma mixing 1. when magma mix together to change the composition Geol 101 Page 117 1. when magma mix together to change the composition ii) Assimilation 1. when magma is ejected into country rock and it becomes assimilated changing the composition Sequence of Silicate Crystallization – 5.8 In general, silicate minerals crystallize in the opposite order they melt — mafic minerals crystallize before (at higher temperatures than) felsic minerals . We can predict the sequence of mineral crystallization with Bowen’s Reaction Series : 11. Use Bowen’s Reaction Series to explain how igneous silicates crystallize through magmatic differentiation. I. Found that mafic minerals are the first minerals to crystallize and they crystallize at the highest temperature. Last Felsic II. Rocks that contain Felsic minerals the minerals that would melt first would be Felsic 12. Compare the crystal lattices of the silicate minerals by drawing simple diagrams of them in the table below (you learned these in Chapter 4). Do the silicate structures become more or less connected as the magma cools ? Magma Composition Temper ature Mineral High Structure (Silicate Chains) Olivine Mafic Minerals Pyroxene Amphibole Intermediate Minerals Biotite Muscovite Felsic Minerals Potassium Feldspar Geol 101 Page 118 Feldspar LOW Quartz Magma Composition and Plate Boundaries (Sections 5.9 – 5.11) 1. For each tectonic setting shown below, indicate the type of melting that occurs and the type of magma that is generated, and where appropriate, the types of rock or features formed from that magma. Tectonic Setting Type of Magma Generated Type of Rocks or Features Formed Mid- Ocean Decompression because magma rises causing the Ridges ridge spreading apart allowing the magma to release. Asthenosphere rises Mafic (due to partial melting of ultramafic mantle Pillow Basalt Gabbro is below as an intrusion Continenta l Rift Divergent Boundaries Type of Melting Magma mixing crystals settling produces intermediate eruptions Decompression melting that happens to be below continental crust. Heating will happen in the continental crust because of Melting of continental by the injection of the magma from below heating produce felsic intrusion Convergent Subduction Melting by water getting incorporated into rock. Minerals are lifting and liberating to help melting. Boundaries Zones Water circulates in the ridge added in pores and in minerals here and also at trench released at depth. Adding water to hot mantle Partial and Total melting of ocean crust produces intermediate and mafic eruptions Possibly melting by heating Continenta Adding water Partially melts ocean crust and mantle l Collisions Form intermediate and mafic magma Rising magma melts intermediate and felsic crust Hot Spots Hot Spots in Oceans Melting by decompression • Rising mantle plume • Crustal melting causes felsic magma and calderas on continents Hot spots in Continents Felsic magma intermediate lava Felsic intrusions • Oceanic Islands ○ Huge Basalt flow also on continents Intrusive (Plutonic) Rock Bodies (Section 5.12 – 5.13) 1. What is the difference between intrusive and e xtrusive igneous (magmatic) features? 1. Define the size, shape and formation of the following intrusive rock bodies: a. Dikes (―dykes‖) 1) vertical walls or tables of magma that have cracked the crust and intruded through b. Sills 1) same as a dike but horizontal and parallel c. Batholiths d. Volcanic Neck e. Vains 1) tiny intrusions on the order of centimeters a) what gold occur in Pasted from <file:///C:\Users\Brandon\AppData \Local\Temp\18cjdms5.tmp\Lesson%204%20Study%20Guide.doc > Geol 101 Page 119 Granite intrusions Geol 101 Page 120 Investigation 5 Tuesday, May 17, 2011 10:33 AM Geol 101 Page 121 Geol 101 Page 122 Geol 101 Page 123 Geol 101 Page 124 Lesson 5 Thursday, May 19, 2011 11:30 AM V olcanoes can erupt: • Pyroclastics ○ Fiery Particles • Gases Crater at the top of the central vent. Craters are much smaller than Calderas. 10's to 100's of feet across Side Eruption Geol 101 Page 125 Geol 101 Page 126 Geol 101 Page 127 Geol 101 Page 128 Geol 101 Page 129 Geol 101 Page 130 Geol 101 Page 131 Geol 101 Page 132 Geol 101 Page 133 Geol 101 Page 134 Geol 101 Page 135 Geol 101 Page 136 Geol 101 Page 137 Geol 101 Page 138 Geol 101 Page 139 Geol 101 Page 140 Geol 101 Page 141 Geol 101 Page 142 Geol 101 Page 143 Geol 101 Page 144 Geol 101 Page 145 Geol 101 Page 146 Geol 101 Page 147 Geol 101 Page 148 Geol 101 Page 149 Geol 101 Page 150 Geol 101 Page 151 Geol 101 Page 152 Geol 101 Page 153 Geol 101 Page 154 Geol 101 Page 155 Geol 101 Page 156 Geol 101 Page 157 Geol 101 Page 158 Guide Thursday, May 19, 2011 11:31 AM GEOL 101 Lesson 5 Study Guide Chapter 6—Volcanoes In addition to your textbook, please view the tutorials provided in the ―Suggested Websites‖ folder in Blackboard. Volcano Types (Section 6.1) 1. Compare each volcano type by filling in the table below: Volcano Description Type/Sketch Typical composition of Lava Shield (Section 6.4) Mafic Lava Largest Volcano and had very broad convex upper slopes Convex Up Largest volcano on earth is Manna Loa Shield Volcano Example - Kilauea Scoria Cones Smallest volcanoes that shoot out rock called scoria that a symmetrical (cinder cone) squeezed out from bottom by plank eruption and built by pyroclast can occur on side of shield same lava Composite (Stratovolca noes) Scoria (basalt with many vesicles) Mafic Lava (Basalt) symmetrical have concave upward shape Felsic to Intermediate lava Mount St. Helens concave upward Volcanic Domes Sunset Volcano Volcanic Domes of felsic lava that ooze out like toothpaste made of a very viscous magma. typically form at the central vent of composite volcanoes, problem is that it usually plugs the central vent and pressure can build up. Felsic 2. Compare the s izes of volcanoes . Which of the volcanoes above is largest? Which is smallest? Eruption Style (Section 6.2) 3. Describe the following types of volcanic eruptions: Lava Eruptions: Lava Flow Lava Dome Obsidian: V olcanic glass Vesicular Rocks (Pumice) Both of these have Vesicles caused by gases Geol 101 Page 159 Both of these have Vesicles caused by gases (Scoria) Pyroclastic Eruptions Lava Fountain when lava is spattering up with tons of lava shooting up Tephra Loose ash and lapilli that has settled on the ground Ash - rock name is tuff, Powder, which is microscopic volcanic glass typically comes from the eruption column and when it falls its called a ash fall or a Tephra fall. when it falls and tears things up. Tuff Formed by ash and Lapilli. Layer of these things that have fallen to the ground as a layer. If gas is present they will fuse together and they will form a welded tuff. it’s a layer of unconsolidated rock Volcanic Breccia signifies a violent volcanic eruption. it is a rock made from an explosive eruption that includes volcanic blocks and bombs Volcanic Bombs formed from Breccia. Eruption Column a burst of ash that is ejected into the atmosphere Pyroclastic Flow A hot (up to 800 C) poisonous mixture of gas and ash moving down slope at speeds Volcanic Blocks are large parts of lava angular that started to cool and then was propelled out of the volcano Fumaroles sometimes yellow because of sulfur some gases include H2S, HF, H2SO4 Acid Magma Viscosity (Section 5.7 and Section 6.2) 4. Compare low viscosity and high viscosity magma. i. Viscous lava Oatmeal 1) Resists flow 2) Very thick 3) Traps Gas ii. Low Viscosity Milk 1) Gas can escape 5. Temperature: What is the effect of temperature on viscosity? • Higher temperature has lower viscosity • Basaltic lava flows quickly on the surface that those in lava tubes • The lava in the tubes is less viscous than the lava flowing on the surface 6. Composition: Compare the viscosity of felsic magma with abundant silicate chains to mafic magma with fewer silicate chains. i. Felsic magma is more viscous than Mafic because of silica 1) So Felsic intermediate magma is more explosive a) Doesn’t let gases escape b) Rhyolite lava c) Erupts at lower temperatures ii. Low viscosity is Mafic lava 1) Low silica chains 2) Basaltic lava 3) Erupts as higher temperatures 7. Dissolved water and volatiles : Describe the effect of water and volatiles on the viscosity of magma. Lava with the higher dissolved water and volatiles they are more viscous so you move from Pahoehoe to aa 8. Compare how gases escape from felsic versus less mafic lava. Volcanic Features of Basaltic Magma (Sections 6.3 – 6.6) 9. Compare aa to pahoehoe lava. 10. Compare how s coria forms to how non-vesicular basalt forms. 11. What is a pillow basalt and how does it form? i. Forms underwater in basalt or when the lava enters water 12. What types of materials would you find erupting from a s coria cone ? i. Pryroclastic 13. What types of materials would you find erupting from a s hield volcano? i. AA lavas because sheild volcanoes generally erupt lava 1) High viscosity basaltic lava 14. Compare eruptions from shield volcanoes to scoria cone eruptions. 15. What is a fissure eruption, and where on earth do they occur? Geol 101 Page 160 V olcanic domes emit felsic lava 15. What is a fissure eruption, and where on earth do they occur? 16. What are flood basalts , and where does the magma for flood basalts originate? i. layers and layers of basalts formed by fissures in the earth that cracked the crust and huge volumes of basalts poured out . 1) this can happen through a rising mantle plume like a hot spot 17. What is the difference between a hazard and a risk? 18. Describe the hazards associated with basaltic eruptions : Falling objects: Gases: Volcanic Ash: Lava: Flooding: Composite Volcanoes and Features (Sections 6.7 – 6.9) 19. Describe the features associated with composite volcanoes: Feature Description/Explain why feature is a hazard Eruption Column and Ash Fall column of tephra and gas that rises upward many of kilometers into the atmosphere Pyroclastic Flows/Ash flow tuffs Landslides rain and snow melt mix with loose ash and rocks on the flanks causing a volcano related mudflow called LAHARS hazardous because of steep slopes loose rocks and abundant clay minerals produced when hot water interact with the volcanic rock Lahars hazard because it can flow long distances form the volcano Lava Flows/Lava Composition Characteristic Rocks Ash, lava, mudflow, Andesite, Mudflow deposits, tephra from eruption column, Tuff from pyroclastic flows (Felsic intermediate) Debris Avalanche when the Pyroclastic Flows most violent eruptions when the eruption column collapses downward as a dense swirling cloud of hot gases Lava Domes (Volcanic Breccia from break up of flowing lava and collapse) (Tuff and Volcanic Breccias associated with dome collapse) Acts as a plug and can be blown away by build up of gases Phreatic Explosion caused by a lateral blast that propel the mountain out ward 20. Summarize the events that caused the following natural disasters: Mt. Vesuvius, 79AD Mt. Pelee, 1902 Mt. St. Helens, 1980 – include before, during and following the main eruption. 21. Compare s hield volcanoes and composite volcanoes. Which one is more hazardous? Why? 1) Composite Volcanoes are more explosive because of the types of lava that are present Calderas (Sections 6.10 and 6.11) 22. Summarize the following about calderas: Large basin shaped volcanic depression. typically has a low central part surrounded by a topographic escarpment Describe the process of caldera formation 1) crustal melting of felsic magma the magma rises and accumulates in one or more chambers. the chamber or chambers may be with in centimeters of the surface 2) Magma reaches the surface and eruption begins. as chamber loses materials the roof of the chamber Geol 101 Page 161 2) Magma reaches the surface and eruption begins. as chamber loses materials the roof of the chamber subsides to occupy the space that is being vacated curved fractures allow crustal blocks to drop 3) Erupting felsic magma forms eruption columns and pyroclasitc flows 4) As the eruption subsides magma rises through fissures along the edges or in the interior erupting on the surface to make volcanic domes (can form lakes or be filled with sedimentary and volcanic deposits What type of magma generally forms calderas? In what types of tectonic settings are calderas generally found? □ Hot spots Continental Oceanic Composite volcano hot spots have large enough eruptions for calderas □ Subduction Volcanoes Compare volcanic craters to calderas – are they the same, are they different, why? How did the Yellowstone Caldera form? □ found in a continental hot spot What is the tectonic setting of the Yellowstone Caldera? Volcanic Hazards and Tectonic Setting (Section 6.12) 23. Volcanic hazards are associated with specific tectonic settings. This is because, as you learned in Chapter 5, different magmas are generated in different tectonic settings. Using the table you filled - out in question #13 of your Lesson 4 study guide, and the risk map shown in section 6.12, fill- out the table below. Tectonic Setting (Type of Plate Boundary or other feature) Magma/Rock Composition Type of Volcano or volcanic feature Mid- Ocean Ridges Mafic Fissures Continental Rift Felsic, Intermediate possibly Mafic Calderas and Domes (East Africa) Subduction Zones pyroclastic and Felsic to intermediate Composite , Possible Calderas Volcanic Domes Continental Collisions Felsic, Granite Rhyolite none because of the extremely Felsic magma and gets trapped in the lava dome Divergent Boundaries Convergent Boundaries Hot Spots Hot Spots in Oceans (Hawaii) Mafic with Basalt Shield Volcanoes (largest volume of basaltic magma in one place) Hot spots in Continents Caldera (huge eruption because of the Felsic Magma) (Yellowstone) Felsic 24. Where are the largest concentrations of composite volcanoes in the world? Explain why you find composite volcanoes in this location. i. Ring of fire around Subduction zones > Geol 101 Page 162 Highest Granite Rhyolite Domes Compostie Diorite Andosite Gabbro Comatite Shield Basalt scoria Cones Basalt Peridotite Highest Pasted from <file:///C: \Users\Brandon\AppData \Local\Temp\kywwq7eo.tmp\Lesson%205%20Study%20Guide%20(Ch.6)%20-%20GEOL% 20101.doc> Subduction Zone Island Arc Geol 101 Page 163 Lesson 6 Monday, May 23, 2011 10:28 AM Geol 101 Page 164 Geol 101 Page 165 Geol 101 Page 166 Geol 101 Page 167 Geol 101 Page 168 Geol 101 Page 169 Geol 101 Page 170 Geol 101 Page 171 Geol 101 Page 172 Geol 101 Page 173 Geol 101 Page 174 Geol 101 Page 175 Geol 101 Page 176 Geol 101 Page 177 Geol 101 Page 178 Guide Monday, May 23, 2011 11:24 AM GEOL 101 Lesson 6 Study Guide Chapter 15—Weathering, Soil, and Mass Wasting In addition to your textbook make sure you view the tutorials in the ―Suggested Websites‖ folder for this lesson in Blackboard. Introduction 1. Explain the difference between weathering and e rosion. weathering: □ the in- place physical and chemical breakdown of sediments and rocks when they are exposed to land surface. Erosion □ Carries the particles away 2. Explain why weathering is important. 3. Explain why rocks weather in terms of mineral stability. a. How stable are the mineral of rocks • Rocks subjected to new temperature and pressure conditions • At a surface where it can be physically broken • Interacts with atmospheric oxygen • Rock Interacts with water which can break down mineral bonds □ Less stable will break down more rapidly □ More stable will take longer Physical Weathering (Section 15.1) ○ Heating and Cooling ○ Frost Wedging ○ Mineral Wedging ○ Root Wedging ○ Burrowing Animals 4. What is the role of joints in weathering? a. Fractures within rocks 5. List and briefly describe the different types of physical weathering processes. Type of Physical Weathering Frost wedging (from ice) Process when snow falls on the ground melts and lodges into the joints of the rock they freeze and expand causing pressure on each side of the cracks wedging the rock apart along the joints. Pressure release (half dome) (Sheeting) (Exfoliation) The rock breaks off into sheets like onion. form from pressure release. Granite intrusions form inside the earth uplifts after crystallization and now under lower pressure the crystals start to expand creating small cracks in mineral crystals and become large parallel cracks that become sheeting joints Thermal expansion and contraction heating causes expansion and then lower temperature causes contraction causing cracks to become bigger Mineral wedging (salt crystal growth) instead of ice wedging rock apart minerals spread rocks apart Root wedging/organisms As the trees grow the roots crack the rocks as well as animals burrowing into the rock. Geol 101 Page 179 6. Remember the role that fracturing plays in physical weathering: the greater the surface area e xposed on a particle, the more surface area there is for chemical attack, and the faster chemical weathering can occur. And, the surface area of a handful of small rock particles is greater than one whole rock. See for yourself by doing the calculation below: Calculate the area of one side of the boulder (A = L x W) Calculate the surface area of the whole boulder. (A cube has 6 sides so, Surface Area = Area x 6) Calculate the surface area of all the cubes if the boulder is split into 8 equal cubes (each cube being 2 cm on a side). 4 cm Physical weathering makes the way for Chemical weathering it takes 500years to make cm of soil Chemical Weathering (Section 15.2) 7. For the three types of chemical weathering below, provide an explanation of what it is and an example chemical reaction: The lower the PH the higher the concentration of Hydrogen ions Type of Chemical Weathering Example Chemical Reaction Dissolution (Example: Limestone) Calcite (the mineral in the rock Limestone): CaCo3+ H2CO 3 Calcite + Carbonic Acid Oxidation 2(HCO3) Bicarbonate Ion in Solution Pyroxene (a mineral common in Mafic igneous rocks): 4FESi03 +O2 Pyroxene Oxygen Hydrolysis Example (Clay) Ca2 + Calcium Ion 2Fe2O 3 + 4SiO 2 Hematite Silica (in water) Potassium Feldspar (a mineral common in felsic igneous rocks): K- Feldspar + Water Kaolinite (clay) + Potassium (in water) + Silica (in water) 8. What is the s alinity of sea water, and why is sea water saltier than river water? How does weathering make the ocean salty? a. the ions from weathering enter the ocean and collects and water is evaporated so the salinity of the ocean 3.5% Salt, 35lbs of salt per 1000lbs of Water Fresh water 0.5 % Salt • Ocean maintains form evaporation, Freshwater and the settling out of precipitates Weathering Products, Controls and Rates (Sections 15.3 and 15.4) You will want to view the Weathering tutorials in your ―Suggested Websites‖ folder for the lesson to answer some of the following questions: 9. What are the products (weathered material) from physical weathering? 10. Rocks that have been fractured or broken up 11. What are the 3 products of chemical weathering? Physical Particles Geol 101 Page 180 11. What are the 3 products of chemical weathering? ○ Physical Particles ○ Ions in solution ○ New Minerals 12. The minerals in the list below are arranged according to their chemical stability. (This chart is in the weathering tutorial). Inspect the list and answer the following questions: Least Stable Halite Calcite Olivine Ca-rich feldspar Pyroxene A mphibole Na-rich feldspar Muscovite Mica Quartz Most Stable Clay Minerals and iron oxides Why are halite and calcite at the top of the list? Solubility Explain the stability of olivine through quartz in relation to Bowen’s reaction series Quartz crystallizes late because it is a high silicate mineral making it resistant to weathering Why are clays and iron oxides at the bottom of the list? □ Covalent bonds □ Form at the surface from weathering Explain why most beaches are made of high percentages of quartz in terms of mineral stability and the rock cycle. because the sands are derived from the weathering and erosion of the land masses and their mountains. The land masses and mountains are composed of rocks that are in turn themselves composed of many common minerals, such as quartz, feldspar, pyroxenes amphiboles and mica, for example. During the weathering process ground waters and dissolved carbon dioxide react with the rocks to break them down. Quartz has the particular ability to survive because it very stable (unreactive to weathering processes) and because it very hard 13. On the following table, explain how each factor affects weathering: Factor Rock Type/ Composition Explain and give examples Compare the weathering of the following rock types: Granite and quartz-rich rocks: Stable compared to marble because of the composition of the rock marble is metamorphic rock made of Mafic igneous rocks: limestone because of oxidation these rocks are weathered more quickly than granite Limestone, rock gypsum and rock salt: less stable than the granite rock because it is made of limestone which consist of calcite Climate Compare the types of weathering you would find in the following climates: Warm/Wet climates: Cold/humid climates: Dry Climates: Time How long does it take for rocks to weather and soil to form? Geol 101 Page 181 Time How long does it take for rocks to weather and soil to form? 14. Describe the temperature and precipitation conditions you would find the following types of weathering, and name the type of climate you would find it in: Mostly chemical weathering: Mostly physical weathering: Both physical and chemical weathering: 15. Define each of the following weathering landscape features and explain how each forms: Exfoliation domes : Spheroidal weathering: Differential weathering: Soil (Section 15.5) 16. Loose, decayed rock debris overlying unweathered bedrock is called ___________. 17. Identify and explain how each of the soil horizons formed in the soil profile below. Mass Wasting (Sections 15.7 – 15.10) In addition to your textbook, you will enjoy viewing the videos and tutorials provided in your ―Suggested Websites‖ lesson folder on Blackboard. Mass Wasting - downhill slope of a mass (large area of material Rock, Unconsolidated Material: Sand Clay Soil, or anything that hasn’t been hardened into rock) • Rock Materials Slide= when materials slide downhill Tennessee Rock Slide, 2009 • Debris = sand, clay, and boulders • Debris flow = is when debris seem to flow down hill (Example: La. Conchita, CA) • Mud Flow= 18. Explain how gravity effects slope stability in terms of s lope angle , and the normal and shear components of this force. Steep slopes are more subject to mass wasting • Normal Component the perpendicular force of gravity • Sheer Component horizontal force of gravity □ Much greater in a steeper slope 19. Explain how the following three factors control slope stability: a. Angle of repose: 1) Maximum angle at which a pile of unconsolidated particles can rest without sliding. Solid rocks can have sheer cliff faces (90 °) when its at its angle of repose it is considered to be in equilibrium with its environment b. Water: 1) Water can make damp sand stick together. 2) A little bit of water can increase cohesion and slope stability a) attracts the grain and makes them hold together better because of the polarity 3) Saturated sand (too much water) the pressure overcomes the tendency of Geol 101 Page 182 normal Sheer Horizontal Steep Slope angle 3) Saturated sand (too much water) the pressure overcomes the tendency of polarity and pushes apart the bond and suspends the friction decreasing the cohesion. 4) Water is the Enemy of Slope stability a) increases pore pressure decreases cohesion, friction and slope stability b) saturated materials increases c. Fractures, cleavage and bedding (geology) 1) Cleavage - Fractures in metamorphic rock 2) Bedding - Parallel to slope stability i) both allow water to get into rock and decrease the cohesion and friction between the layers of the rock 20. Explain how the following triggers can cause a mass wasting event: Trigger: External influence on a slope that can through it out of equilibrium. Explanation Precipitation can saturate sediment weakening an unconsolidated material by reducing grain to grain contact (over saturation) Wildfires Overloading more on top of the slope than the slope is use to Undercutting/ Oversteepening undercutting the toe of the slope can be cause by humans or rivers Volcanic Eruptions can shake fracture and tilt the ground unleashing landslides from over steepened slopes can cover an area with hot ash causing melting ice and snow releasing large amounts of water and mobilize volcanic material in a debris flow Earthquakes 21. Differentiate between the following types of mass wasting (landslides): a. Rock Falls: 1) free fall of large blocks or smaller pieces of bedrock detach from cliff face and fall until they smash into the ground b. Rock Avalanche : 1) particles support each other by collisions ride down slope on a cushion of air c. Rock slides: 1) rocks are attached to the bottom and sliding along a lubricated plane that has clay and water. downhill movement of rock along a plane d. Rotational slides (slumps): 1) downhill movement of unconsolidated materials down hill. 2) Slump block is the piece of material that slide downhill e. Debris slides: 1) Pile of debris that move downhill that is attached to mass f. Earth flows, debris flows, mud flows: 1) Debris flows and mud flows a) Fast b) difference is in the material which it moves c) both involve water d) Debris : Boulders Mud: Small Clay 2) Earth Flows and Creep a) Earth Flows: i ) Involve water and flow very slowly i i) can start as a slump but water is mixed and begin to move slowly iii) like mud flows b) Creep i ) Most expensive i i) soil is creeping slowly down slope 22. January 2005 La Conchita Disaster: Visit the La Conchita website in your ―Suggested Geol 101 Page 183 22. January 2005 La Conchita Disaster: Visit the La Conchita website in your ―Suggested Websites‖ folder site and outline the precursor events and triggering mechanisms that caused the January 2005 La Conchita disaster. a. in southern California b. caused by precipitation c. debris fall 23. Which of the types of landslides you list in #21 above would best characterize the La Conchita disaster? Pasted from <file:///C: \Users\Brandon\AppData \Local\Temp\k7jkm0in.tmp\Lesson%206%20Study%20Guide%20(Ch.15%20 -% 20Mass%20Wasting).doc> Geol 101 Page 184 Investigation 15_14 Tuesday, May 24, 2011 10:28 AM Geol 101 Page 185 Snow Geol 101 Page 186 Lesson 7 Wednesday, May 25, 2011 9:52 AM Geol 101 Page 187 Geol 101 Page 188 Geol 101 Page 189 Geol 101 Page 190 Geol 101 Page 191 Geol 101 Page 192 Geol 101 Page 193 Geol 101 Page 194 Geol 101 Page 195 Geol 101 Page 196 Geol 101 Page 197 Geol 101 Page 198 Geol 101 Page 199 Geol 101 Page 200 Geol 101 Page 201 Geol 101 Page 202 Geol 101 Page 203 Geol 101 Page 204 Geol 101 Page 205 Geol 101 Page 206 Geol 101 Page 207 Geol 101 Page 208 Geol 101 Page 209 Geol 101 Page 210 Geol 101 Page 211 Geol 101 Page 212 Geol 101 Page 213 Geol 101 Page 214 Geol 101 Page 215 Geol 101 Page 216 Geol 101 Page 217 Geol 101 Page 218 Guide W ednesday, May 25, 2011 11:23 AM GEOL 101 Lesson 7 Study Guide Chapter 7—Sedimentary Rocks In addition to your textbook, see the ―Suggested Websites‖ in your Lesson folder for helpful animations and tutorials that will help you answer questions below. . Clastic Sediments (Section 7.3 and 7.4) TYPES OF CEMENT 1. Be able to outline and describe the four processes that form sediment and sedimentary rocks: a. Weathering: source b. Erosion/Transportation: water, wind, glaciers, mass wasting, (HOW) Calcite hematite clay quartz c. Deposition: occcurs when current energy is not great enough to transport particles d. Lithification: digenesis=lithification (buried) compacted (pressed) Cemented - glue refers to minerals that precips in pore space to and hold grains together. Mechanism: Suspension - Clay Silt Saltation: skipping and Jumping - Sand Rolling - larger particles (gravel) Lowest Gradient =slope Greatest energy 2. Compare the sizes of clastic grains: Gravel: Sand: Mud: 3. Explain how the following attributes of clastic sediments change with distance from their source: a. Size of grains: b. Shape of grains: Which of the particles above was probably deposited furthest from its source? How can you tell? c. Composition of grains: d. Sorting: the further you are from the source the better sorted Boulders/Gravel- Basketball, golf ball sized Sand - MM (table Salt) Clay/silt- <mm (powder) Textural Term Poorly sorted Explanation/Example Well sorted 4. Where on Earth (what environment) do you think a well- sorted sand could form? Why? Well sorted samples would be found at a beach a. Far from source Geol 101 Page 219 Away From Source • Grains become smaller • grains become rounded • Composition becomes enriched i n more resistant minerals (like quartz) • Better Sorted b. and has wave actions 5. Where on Earth (what environment) do you think a poorly sorted sediment could form? Why? a. Poor sorted would be in mountains a. Rock was created close to source b. near mountain Clastic Sedimentary Rocks (Section 7.5; 7.7-7.8) 6. Explain how rocks become lithified a. Burial and compaction: first are buried and compacted b. Cementation: then are cemented by minerals 7. What are the four most common types of cement? Calcite hematite - black reddish clay - dark colored quartz - Light colored tan/gray formed by dissolution of the old grains 8. In the chart below, for each grain size, give the approximate size and the rocks that would result from each type of particle. Particle and name Rounded gravel (boulders, cobbles, and pebbles) How Formed? Environment of Deposition? Channels poor sorted Cobble beaches Well sorted Name _Conglomerate the size of the grains make it what it is. Angular gravel (boulders, pebbles, and cobbles) formed in mountain stream land slide Name Breccias____ based on angular shape Mass wasting events Sand Name Sandstone_____ Beaches Sand dune River -point bar (sand bar) Delta -transitional Shelf Well sorted sand sized grain are left behind and compiled and become cemented together over time Silt Siltstone Name ________________ Clay * Loess • Sitstone • Mudstone • Shale Found: • Floodplain • Lake • Wind • Shallow seas • Bays Lagoons • Low energy areas • Lakes Geol 101 Page 220 Photo Shale Name _________________ • Lakes • Lagoons • offshore • any place with low current energies • quiet water places • possible flood plains 9. Rocks that are made of the largest particles needed high energy for the particles to be transported. Which of the rocks above needed lots of energy for the transportation of its particles? Conglomerates and Breccias need high energy for transportation Sandstone takes a moderate amount of energy but at a beach sands take lower energy 10. What environments of deposition would be considered high energy? • beaches • Sand dunes • mountain fronts • Places with high wind currents (beaches deserts) • Rivers 11. Rocks that are made of the smallest particles need low energy environments for deposition. Which of the rocks above need low energy for the transportation and deposition of its particles? Siltstone Shale 12. What environments of deposition would be considered low energy? a. Lakes b. Lagoons c. flood Plaines d. middle of oceans 13. Explain how shale forms and in what environments of deposition it forms. Made up of clay and can be found in the middle of a lake or in the middle of an ocean. Chemical/Biochemical Sedimentary Rocks (Section 7.6; 7.11) Derived from precipitation of inorganic ions and compounds in solutions Ions include: 14. Fill in the chart below to summarize the chemical and biochemical sedimentary rocks. Rock Name Chemical Composition/How Formed? Environment of Deposition? Rock Salt Gypsum Limestone Travertine Geol 101 Page 221 Photo Dolomite See Dolostone Chalk Chert from the dissolved shells of microorganisms that secrete SiO2 (silica) to make their tests Chert is hard Iron Formation Coal comes out of a coal seem forms in a swap where there is lots of vegetation that falls and dies forming Peat then under compression becomes Lignite then bituminous coal (most abundant in US)then becomes Anthracite (pure carbon) causes coal 15. Explain what e vaporites are and how they form. Rocks that were water evaporates and it leaves behind ions that come into contact with each other. H+ NA+CLNaCl Halite to Rock salt Co3 Calcite- > Limestone Precipitation: when ions form solids Precipitate is a mineral solid inorganic Chemical sedimentary rock - Gypsum Evaporates are a type of chemical sedimentary rock Arid places with restricted lakes (lake in dessert, Restricted lagoons) 16. Give three types of sedimentary rocks that can form as evaporates. a. __Gypsum _Rock Gypsum ___ b. ___Rocksalt_______________ c. ___inorganic limestone (small amounts) 17. Explain how and where biochemical limestone forms. formed by the dissolved tests of microorganisms like foraminifera They are made of Ca3 Sand of Calcite shells goes through diagenesis (lithification) to get limestone found on carbonate platforms (Bahamas) ○ water is clear because there is no clasitc input (rivers aren't draining into this area) 18. How is chert different from limestone? 19. Draw a diagram showing the different steps involved in the formation of coal, and label the different types of organic material formed at each step. Vegetation Peat Bituminous Coal (sedimentary coal) Anthracite Coal (pure) 20. Section 7.11: How do carbonate rocks form in non- marine environments? Geol 101 Page 222 Travertine: When ground water that is super saturated with dissolved calcium and carbonate calcite precipitates forming travertine Dolostone: when Mg rich ground water interacts with limestone 21. Section 7.11: How do carbonate rocks form in marine environments? Sedimentary Structures (Section 7.7) 22. Explain how the following sedimentary structures form: Structure Strata (Layers, Beds) What is it/ How formed? formed by deposition right after suspensions Current Ripples (asymmetrical Ripples) Gentle slope and steep slope. RIVERS in rivers with sand bed. current pushes grains up to top of ripple and when slope exceeds angle of repose the grains cascade down making a layer and ripples can migrate over time then you get current Ripples formed by unidirectional currents. Current is always opposite the steep side. the gentle slope is the direction in which the current is coming from. Wave Ripples OCEANS Symmetric Ripples there is no steep or gentle side but all the sides are equal as far as the angles. Forms when tide comes in on beaches and then goes back out. wave ripples are indicators of current motion that is bidirectional. when we see sandstone with wave ripples we can say that the environment is in water induced by wave action on a beach Cross Bedding (Navajo Sandstone) 23. What is a formation and how is a formation different from other strata a. a continuous layer of rock that has same composition everywhere Transgressions and Regressions (Section 7.12) You can use your textbook and the following animation of transgressions and regressions to answer the following questions. ions/ch5.htm# 24. What is the difference between a transgression and regression? 25. Draw a stratigraphic section that represents a transgression. Explain how you know your section represents a transgression. 26. Draw a stratigraphic section that represents a regression. Explain how you know your section represents a regression. Pasted from <file:///C:\Users\Brandon\AppData\Local\Temp\kxf7pbrg.tmp\Lesson%207%20Study%20Guide%20(%20Ch.7%20 -% Geol 101 Page 223 Pasted from <file:///C:\Users\Brandon\AppData\Local\Temp\kxf7pbrg.tmp\Lesson%207%20Study%20Guide%20(%20Ch.7%20 -% 20Sed.%20Rks.).doc> Geol 101 Page 224 Investigation Thursday, May 26, 2011 12:37 PM To complete this worksheet, see the instructions in the textbook (Chapter 7 Investigation). Table 1. Observations and Characteristics of Sedimentary Layers The two photographs below show the upper and lower parts of a sequence of layers. Try to identify boundaries between different sedimentary rock units, and draw a dashed line on the photograph along any main boundary. The stratigraphic section to the right contains some descriptions of the units shown in these two photographs. You do not have to write any observations on this worksheet, but your instructor may have you discuss these in class. Stratigraphic Section Table 2: Interpreting the Sedimentary History from a Stratigraphic Section Using both the stratigraphic section and the cross section located in the textbook (Chapter 7 Investigation), determine the environment of deposition and list supporting evidence for that environment. Then, answer the questions below this table. Rock Unit Interpreted Environment of Deposition of Rock Unit (not what it is like today) (circle all that apply, and list key characteristics that support your interpretation) Upper sandstone and mudstone unit (a) steep mountain front, (b) river system, (c) middle of a lake, (d) sand dunes, (e) sandy beach or delta, (f) plant- rich swamp, (g) coral reef, (h) muddy part of ocean Key characteristics: Dark gray shale (a) steep mountain front, (b) river system, (c) middle of a lake, (d) sand dunes, (e) sandy beach or delta, (f) plant- rich swamp, (g) coral reef, (h) muddy part of ocean Key characteristics: Yellowish- tan (a) steep mountain front, (b) river system, (c) middle of a lake, (d) sand Geol 101 Page 225 Yellowish- tan sandstone (a) steep mountain front, (b) river system, (c) middle of a lake, (d) sand dunes, (e) sandy beach or delta, (f) plant- rich swamp, (g) coral reef, (h) muddy part of ocean Key characteristics: sandstone formed from the cementation of sand Lower basal conglomerate (a) steep mountain front, (b) river system, (c) middle of a lake, (d) sand dunes, (e) sandy beach or delta, (f) plant- rich swamp, (g) coral reef, (h) muddy part of ocean Key characteristics: Question 1: Does the change of environment from the base of the section up to the thick gray shale indicate a transgression or regression of the sea (circle one)? Transgression/Regression List observations that support this interpretation_ sea level rose to a transgression then it regressed downward Question 2: Does the change from the thick gray shale to the overlying sandstone indicate a transgression or regression of the sea (circle one)? Transgression/Regression List observations that support this interpretation Question 3: Which of the following phrases summarizes the history of the entire sequence (circle your answer): (a) transgression, (b) regression, (c) transgression followed by a regression, or (d) regression followed by a transgression? Pasted from <file:///C:\Users\Brandon\AppData \Local\Temp\2bsi5cg6.tmp\07_16_sedimentary_worksheet11.doc > Geol 101 Page 226 Lesson 8(I) Tuesday, May 31, 2011 12:18 AM Geol 101 Page 227 Geol 101 Page 228 Geol 101 Page 229 Geol 101 Page 230 Geol 101 Page 231 Geol 101 Page 232 Geol 101 Page 233 Geol 101 Page 234 Geol 101 Page 235 Geol 101 Page 236 Geol 101 Page 237 Geol 101 Page 238 Geol 101 Page 239 Geol 101 Page 240 Geol 101 Page 241 Lesson 8 (II) Tuesday, May 31, 2011 12:19 AM Geol 101 Page 242 Geol 101 Page 243 Geol 101 Page 244 Geol 101 Page 245 Geol 101 Page 246 Geol 101 Page 247 Geol 101 Page 248 Geol 101 Page 249 Geol 101 Page 250 Geol 101 Page 251 Geol 101 Page 252 Guide Tuesday, May 31, 2011 12:19 AM GEOL 101 Lesson 8 Study Guide Chapter 8—Deformation and Metamorphism Mountain Belts – Ch.11.2 Formation of mountains is a direct result of plate tectonic activity. In addition to your textbook, you can view the ―Volcanic Mountain Belts‖ and Continental Collisions‖ clips in the ―Mountain Building‖ animation in the ―Suggested Websites‖ folder. 1. Mountain building can occur at different types of plate boundaries. In the table below, briefly summarize how the following types of mountains form (the first one is done for you) Type of Mountain How do they form? Example Volcanic Island Arc Ocean- Ocean Subduction Aleutian Islands Continental Arc (Subduction Zones) Andean- type (Subduction Zones) Compression and volcanism Subduction Ocean Crust Andes Mountains Continental Collisions (Largest) Continent- Continent Collisions ocean crust cant subduct and they pile on top of each other causing large mountains Himalayas Mantle Upwellings Hot Spot or Old Hotspot Uplifting of mantle materials and causes cracking and faulting of the overlying crust Yellowstone Hotspot □ Orogeny= Mountain building event Deformation – Ch. 8.2 The results of mountain building are recorded in the earths crust. Earth crust becomes deformed (changes) as a result of the tectonic forces. Deformation is evidenced by geologic structures –faults and folds that have occurred after the rock has been lithified, and metamorphic rocks . Stress Stress is the force the produces change (deformation) in a rock. In addition to Ch.8.2 in your textbook, you can view ―What is deformation‖, ―Brittle Deformation‖, and ―Ductile Deformation‖ in ―Deformation of Rocks – Structural Geology at the following website: 2. What is the difference between confining pressure and differential stress ? Draw a picture showing the difference between the two. ○ Stress is the pressure applied to a rock Confining Pressure □ Same amount of stress from all directions Differential Stress □ Different amounts of stress from different directions □ 3. Define and compare brittle deformation, e lastic deformation and ductile deformation: Deformation- Strain in responses to stress Brittle Deformation Elastic Deformation Ductile Deformation Small stress at shallow Rocks stretch then Geol 101 Page 253 At deep depths increased depths and rocks will begin to break brittley and that is called FAILURE. go back to their original positions. ( not typical ) stress causes a rock to flow or bend 4. Use the following picture to describe how the type of deformation of continental crust varies with depth. 5. How do rocks respond to differential stress ? For each type of stress noted below, indicate how rocks would respond. (faults) Type of Differential Stress Compression Brittle (shallow depths) Reverse Fault Deformation Ductile Deformati on (deeper depths) Fold tension Normal Stretch Rocks (elongated) Shear Strike -Slip Sheared Rocks Identifying Faults – 8.3 – 8.4 6. Differentiate between the following: d. Joints : Commonly vertical. Crack where rock pulled apart or pushed together 1) Formed from Burial and Tectonic Forces 2) Cooling and Contractions a) Columnar Jointing i) Devils Tower- Black hills of South Dakota 3) Unloading- Releasing of pressure (Half- Dome) e. Faults: Rocks have slipped past one another 1) Strike 2) Dip 3) Strike- Slip Fault 4) Dip- Slip Faults 5) Oblique Slip Fault 7. Describe the difference between s trike and dip using the diagram below: Geol 101 Page 254 7. Describe the difference between s trike and dip using the diagram below: respect to north Dip is angle that the rock unit makes with horizontal Strike is the angle that a rock body makes on a map with I. Normal and Reverse/Thrust Faults (Dip-slip Faults) 8. Faults that have some displacement in a cross -section view can be defined as normal or reverse by identifying the hanging wall and foot wall on either side of the fault. Define hanging wall and footwall using the picture below, in your book, or on the website above: Rules: If the hanging wall has moved down in relationship to the foot wall, the fault is normal. If the hanging wall has moved up in relationship to the footwall, the fault is reverse . You determine whether the hanging wall or foot wall has moved up or down by using a m arker bed, such as a sedimentary layer with a distinctive color. 9. Identify the following fault structures and the stress that caused them. Structure (use arrows to show stress causing this structure) Cross- section view: Type Dip-slip or Strike -Slip of Fault (ie. Strike -slip, normal) Stress (ie. Compression, etc.) Normal Tension/Extension Reverse Compression Hanging wall has moved up in relation to the footwall (also label hanging wall and foot wall) Cross- section view: (also label hanging wall and foot wall) Cross- section view: Thrust Fault (Reverse Fault) Geol 101 Page 255 Compression Cross- section view: Thrust Fault (Reverse Fault) Compression (also label hanging wall and foot wall) 10. How can you tell the difference between a normal fault and a reverse fault? Illustrate your explanation by drawing a cross- section of both. 11. Compare the s tress that causes a normal fault verses a reverse fault? 12. Compare thrust faults and reverse faults . 13. Draw a simple cross- section of a horst and graben structure and show the stress that caused this structure. II. Strike -Slip Faults: Right- and Left-Lateral Strike slip faults are identified in map view rather than cross- section, and are defined using the following rule: If you stand on one side of a strike slip fault and look across the fault, determine whether a marker (such as a road or a stream) is offset to the left or the right. If the marker is offset to the left, the fault is left lateral. If the marker is offset to the right, the fault is right lateral. 14. Determine whether the figures below are left- lateral or right lateral: Right Left Folds (Ductile Deformation) – Ch.8.5 15. Anticlines and synclines are the types of folds that are produced by ductile deformation. Identify the following folds as anticlines or synclines: Geol 101 Page 256 following folds as anticlines or synclines: Type of fold: __Syncline_____ Draw- in the axial plane (hinge line) Label the limbs Type of fold: ________anticline _________ _ Draw- in the axial plane (hinge line) Label the limbs 16. If you walked across the top of each fold starting from the hinge line out along the limbs determine if the strata you walk over gets older or younger for each fold: Anticline: The strata is (older, younger) __Younger_ at the hinge line and gets Older as you move away from the hinge line. Syncline: The strata is (older, younger) _____Older _____ at the hinge line and gets ___Younger______ as you move away from the hinge line. 17. What type of s tress causes folds? Using arrows, draw the direction of the stress causing the folds on the diagrams above. Compression 18. Define and describe other types of compression, ductile features: Domes: Basins: Practice Identifying Geologic Structures In Photos 19. Referring to the photo below (shown in cross - section) : f. Identify the hinge of the fold above. Draw it on the photo. g. Identify the type of fold (you did this in 15 above): Anticline Geol 101 Page 257 Monoclines: f. g. h. i. j. Identify the hinge of the fold above. Draw it on the photo. Identify the type of fold (you did this in 15 above): Anticline Note which strata is oldest and which strata is youngest in the photo. Is this fold a s ymmetrical or asymmetrical fold? How can you tell? (see p. 213 in your textbook). What type of stress caused this fold? On the diagram above draw the direction of the stress with arrows. Compression k. Based on the type of stress that caused this structure, in what type of tectonic setting do you think this structure formed? Convergent boundary 20. Referring to the photo below: 1. The following structure is shown in plan view (map view). Identify the type of structure Strike Slip Fault Right Lateral 2. What type of stress probably generated this structure? How can you tell? Using arrows, draw on the photo the direction of stress that probably produced this structure. Shear 3. Based on your interpretation of the structure and the stress that caused it, in what type of tectonic setting do you think this structure formed? Strike Slip Fault Putting It All Together Faults and folds can be used to interpret the type and direction of tectonic stresses that deform the crust and produce mountains. You can use what you learned so far to fill- out the table below. Make sure you can relate the deformation (types of structures) to the stress and tectonic setting that caused them. 21. Fill- in the summary table below (the first one is done for you): Stress Ductile Brittle Tectonic Setting? Geol 101 Page 258 Example on Deformation Deformation Compression Folding Reverse Faults Thrust Faults Convergent Boundaries Earth Extension Stretch Normal Divergent Shear Sheared Strike- Slip Transform Himalayas Metamorphic Textures – Ch. 8.6 22. Compare deformation and metamorphism. Deformation □ the large scale change in rock shape Metamorphism □ Rock that has changed in texture or chemical composition (minerals) in the solid state □ Change of the mineral makeup of a rock □ Small scale □ occurs due to the partial or complete recrystallization of minerals over long periods of time under high pressures and temperatures. 23. Label the photos to show the metamorphic textures and explain how each texture forms: Cleavage: (Foliation) Schistosity (Foliation) Micas under microscope: Gneissic (banding) (Foliation) Metamorphic Rocks – Ch. 8.7 Pressure is required for foliation Geol 101 Page 259 Metamorphic Rocks – Ch. 8.7 Pressure is required for foliation 24. On the following diagram, fill- in the metamorphic rocks that form given the indicated parent rock: Foliated Rocks Non-Foliated Rocks Shale Temp Pressure Sandstone Limestone Low grade: Slate_____ Quartzite_(pressure solution) Marble_(high Temperature Low -no foliation because quartz grains are not very conditions) well compressible. Phyllite ____ _ Schist______ high High grade: Gneiss_____ Types of Metamorphism and Tectonic setting – Ch.8.9 25. Define the following types of metamorphism, and then describe the type(s) of tectonic setting(s) in which they occur. Show where you would find these types of metamorphism in each of the block diagrams below: Regional: forms at high pressure and high temperature. called this because it occurs in mountain ranges associated with convergent boundaries Contact: Hydrothermal: Cataclastic (Fault): 26. For each of the types of metamorphism listed above, show where they would occur on the graph below: Geol 101 Page 260 Pasted from <file:///C:\Users\Brandon\AppData \Local\Temp\ipag51ac.tmp\Lesson%208%20Study%20Guide%20(Ch.8%20 -%20Deformation% 20and%20Metamorphism).doc > Geol 101 Page 261 Lesson 9 Thursday, June 02, 2011 9:54 AM Geol 101 Page 262 Geol 101 Page 263 Geol 101 Page 264 Geol 101 Page 265 Geol 101 Page 266 Geol 101 Page 267 Geol 101 Page 268 Geol 101 Page 269 Geol 101 Page 270 Geol 101 Page 271 Geol 101 Page 272 Geol 101 Page 273 Geol 101 Page 274 Geol 101 Page 275 Geol 101 Page 276 Geol 101 Page 277 Geol 101 Page 278 Geol 101 Page 279 Geol 101 Page 280 Geol 101 Page 281 #12 #13 Finish study guide Radioactive dating problem Do investigation 9 bring print out of 10 Guide Thursday, June 02, 2011 9:54 AM GEOL 101 Lesson 9 Study Guide Chapter 9—Geologic Time In addition to your textbook, the ―Suggested Websites‖ folder for this lesson shows excellent animations and tutorials on geologic time. Part I: Relative Dating Relative Dating Principles – 9.1 1. What is the difference between relative dating and absolute dating (assigning ages)? 2. Define the following: a. Principle of Original Horizontality : sedimentary rocks were originally deposited horizontally on land surface. b. Principle of Superposition: In any sedimentary setting the oldest layers are at the bottom and the youngest are at the top. c. Principal of Inclusions : inclusion are older than the rock that contains them Which is older, the black inclusion in the picture above or the white diorite surrounding it? How do you know? d. Principle of Cross -cutting Relationships : Geol 101 Page 282 d. Principle of Cross -cutting Relationships : Which is younger in the picture above – the fault or the strata it cuts? What type of fault is shown? Which is younger in the picture above – the gray dike or the strata it cuts? e. Baked Contacts: (c) 2005 Andrew Alden, licensed to ( fair use policy) ―The lava flow exposed in this roadcut near Alturas, California, has baked the mud beneath it into brick - red shale‖. (Quoted directly from Unconformities – Ch.9.3 Geol 101 Page 283 3. What are unconformities ? (ie- what do they represent in the rock record?) 4. Define the following and explain how they form: a. Angular unconformities : b. Non-conformities: the boundary between the igneous -metamorphic basement and the sedimentary layer c. Disconformities: an unconformity or surface of non deposition or erosion between parallel sedimentary layers Interpreting Geologic Cross-Sections - Practice 5. The picture below is a cross- section view of an outcrop. Use the stratigraphic principles above to put the labeled geologic events in order. Start with labeling the letter of the oldest event at the bottom, to the youngest event on top. Make sure you include the following events: Fault A (give type of fault) Deposition of strata C Deposition of strata G Erosion I (give type of unconformity) Intrusion of igneous rock N (give type of intrusion) Erosion O (give type of unconformity) Deposition of Strata P Deposition of Strata W Youngest Oldest ( _o__ disconformities _n__ dike _w__ __p_ _i__ disconformities _a__ Reverse _g__ _c_ Superposition Geol 101 Page 284 6. Use stratigraphic principals to develop a geologic history for the outcrop below. Remember to start at the bottom when you interpret the crossection. Fossils – Ch.9.5 through 9.6 7. What are fossils? 1. evidence of past life used to determine relative age and the environment of deposition 8. Describe the different ways in which a plant or animal can be preserved as a fossil: Type of Preservation Hard Parts What is it/how does it form? Shells or Bones/ rapid burial Molds Replacement Carbonization and Impressions Trace Fossils 9. Describe the two main factors that influence whether or not a creature is preserved as a fossil. 10. Define ―faunal succession‖. that fossils that are younger look more like animals of today and fossils found in the older layers of rock look very different than things today 11. Using the figure below, describe the fossil evidence that differentiates each geologic era. In addition, make sure you know the ages of the beginning/end of each era (Ma = millions of years ago). Geol 101 Page 285 New Life Middle Life (looks more like it does today but not quite) Ancient Life 12. What three independent sources of data were used to establish the geologic time scale? a. _____________________________________ b. _____________________________________ c. _____________________________________ Correlation – Section 9.7 13. Formations can be correlated using rock types (lithostratigraphic correlation) and fossils (biostratigraphic correlation). The stratigraphic sections below show different rock types that can be correlated using lithostratigraphy. Complete the exercise below to define and understand the concept of ―correlation‖. a. Draw lines between the three stratigraphic sections below to connect the geologic contacts between beds. You may want to check your textbook to see what this will look like. b. How many beds can be correlated across all three sections? _________ c . How thick is the thickest stratigraphic section (or column of rocks)? (Note that the scale goes from 0 t o 70 meters.) ______________ meters d. A bed of coal (black) is present in sections B and C. How deep would you have to drill in section A (starting at the top of the section, up near the letter A) to reach the buried coal seam? __________ meters Geol 101 Page 286 Part II = Absolute Dating Pleases see your ―Suggested Websites‖ folder for this lesson in Blackboard for important tutorials and animations that will help you with this next section. Radioactive Decay – Ch.9.3 1. What is radioactive decay? Radioactivity □ The breakdown of the nucleus of an atom it will release particles to become stable 2. What is a radioactive isotope ? Half-life 3. What is half-life ? View the following half- life animation in your ―Suggested Websites‖ folder for a demonstration. 4. Approximately what percentage of parent isotopes remains after 2 half- lives have passed? 5. If a rock initially contained 10 milligrams of a radioactive parent when it first crystallized, how much remains after 4 half- lives? 0.625mg 6. Assume a parent isotope has a half- life of 100 million years, how old is a sample that contains 15 % of its original parent isotopes? Use the graph below for your calculations: Geol 101 Page 287 100+50+25=175 2.8*100=280 1.25/2=0.625 .5/4=0.125 .125*5=0.625 Radioactive Dating 7. List 3 isotope pairs that are used to date old rocks. 8. Describe what radioactive isotopes can tell us about the following geologic features: Volcanic Rocks: Igneous intrusions: Sedimentary rocks containing carbon: Sedimentary rocks containing boulders: Metamorphic rocks: 9. Read about radioactive dating of zircons in the attached article and answer the following questions: In what types of rocks do zircons occur? Why are zircons ideal for age- dating the earth? What is the age of the oldest zircon? 10. If you age- date a zircon in a sandstone, are you dating the deposition of the sandstone, the lithification of the sandstone, or the crystallization of the igneous minerals that formed the sandstone? Explain. Radiocarbon (Carbon-14) Dating A photo of the processes involved in carbon- 14 dating is shown below, and is part of a tutorial in your lesson folder: Geol 101 Page 288 11. Which is the radioactive isotope – C- 12 or C- 14? 12. How does C- 14 form? 13. What does C- 14 decay into? 14. What isotope ratio is used to determine the age of a sample using C - 14? 15. What types of materials can be age- dated using C- 14 – organic or inorganic or both? Can granite be age- dated using C- 14? Why or why not? 16. Given that the half- life of C- 14 is only 5,730 years, and there is usually not enough C - 14 remaining in a sample after 12 half- lives, what is the age limit for dating materials using C - 14? Zircon Chronology: Dating the Oldest Material on Earth Backscatter electron image of a zircon crystal showing narrow growth zones around a central core. Photo courtesy of Darrell Henry. Excerpt from EARTH: INSIDE AND OUT, edited by Edmond A. Mathez, a p ublication of the New Press. © 2000 American Museum of Natural History. What are the oldest rocks on Earth, and how did they form? The material that holds the greatest insight into these fundamenta l questions, b ecause it can contain a record of some of the earliest history of the Earth, is a mineral named zircon. For example, a few g rains of zircon found in the early 1990s in a sandstone from western Australia dates back 4.2 – 4.3 billion years, and we know from meteorites that the Earth is n ot much older at 4.56 billion years. Geology professors Darrell Henry of Louisiana State University and Paul Mueller of the University of Geol 101 Page 289 n ot much older at 4.56 billion years. Geology professors Darrell Henry of Louisiana State University and Paul Mueller of the University of Florida are expert practitioners of several techniques that can extract precise age information from zircons. They’re searchi ng for some of the o ldest rocks in the continental crust, for the zircons within them, and for the clues the zircons contain about the formation of the planet. Originally formed by crystallization from a magma or in metamorphic rocks, zircons are so durable and resistant to chemical a ttack that they rarely go away. They may survive many geologic events, which can be recorded in rings of additional zircon that grow around t he original crystal like tree rings. Like a tiny time capsule, the zircon records these events, each one of which may last hundreds of mi llions of years. M eanwhile, the core of the zircon itself remains unchanged, and preserves the chemical characteristics of the rock in which i t originally crystallized. Zircon contains the radioactive element uranium, which Dr. Mueller calls ―the clock within the zircon‖ because it converts to the element lead at a specific rate over a long span of time. According to Mueller, this makes zircons ―the most reliable natural chronometer that we have when we want to look at the earliest part of Earth history.‖ He goes on to explain that there are two ways to tell time in geology . ―One is a relative time, meaning if there’s a mineral of one kind, and growing around it is a mineral of a second kind, you know the inner miner al formed first, b ut you don’t know how much time elapsed between the two.‖ Henry evaluates these kinds of mineral relations in rocks. From th e types of minerals and their distributions in the rocks he reconstructs a relative sequence of events that reflects the change over tim e of parameters like p ressure, temperature, and deformation. ―If I have a metamorphic rock,‖ elaborates Dr. Henry, ―I can use the types of mineral s and their chemistry to determine the conditions that the rock had experienced at some point in its history. For example, a temperature o f 700°C and high p ressure of several thousand times atmospheric pressure imply that it had been deep in the crust at some time during its geol ogic history.‖ He infers what has happened to the rocks, but not how long ago it happened. That’s where the second kind of time comes in: absol ute as compared to relative. ―We try to supply the when,‖ explains Mueller. ―My job is to look at the chemistry of the rock, includi ng its isotopes, and try to derive the absolute times for events that are recorded in the rock and its zircons.‖ How precise are those actual numbers? ―Depending on the history of the rock, we can date things nowadays down to something on the order o f a few hundredths of a percent of its age,‖ answers Mueller. That translates, for example, to plus or minus a million years out of three b illion. Carbon -14 dating can go no further back than about 70,000 years, because the half -life of carbon -14 is only 5,730 years. (The half -life is the time it takes for half of the original radioactive isotope to change to another element.) In comparison, the half -life of the radioactive u ranium 238 isotope is 4.5 billion years, which makes it useful for dating extremely old materials. Zircon chronology begins in the field. ―You go out and look for relative age relationships, see which rock unit was formed fi rst,‖ says Henry. ―For example, there may be a granite which contains pieces of other types of rocks enclosed in the granite. Because of their p osition, we know that the rocks enclosed in the granite have to be older.‖ Geologists map an area to identity these relative age relationships . Then they collect s amples, which weigh from two to more than one hundred pounds, depending on the rock type. Zircons aren’t rare; in fact, they ’re common in g ranitic rock. But they are tiny grains that make up only a small fraction of any given sample, typically less than a tenth o f one percent, and they’re dispersed throughout the rock. This makes separating out the zircons a painstaking process. The rock is ground up to b reak it into individual mineral grains. Then, ―because zircon is more dense than almost any other mineral, we put the ground -up rock in a liquid with very h igh density so that only the densest minerals fall through to the bottom,‖ explains Henry. In other words, says Mueller, ―zi rcons sink. We also use the magnetic qualities of the zircons to separate the most pristine ones from the rest.‖ Then the detailed geochronology work begins. ―I’ll take a fraction of those zircons, make thin sections of them —slices of mineral thirty micrometers thick, roughly as thick as a hair, that are mounted on glass —and get an idea of what they look like in terms of zoning pattern, whether they underwent multiple episodes of growth, how simple or complex they are,‖ says Henry. He passes this information a long to M ueller, along with the sample’s geological context. ―I also look at a thin section of the rock to learn something about the framework in which the zircon occurs. Is it in a granite? Or is it in a metamorphic rock that has had a more complex history? Or is it a metamor phosed sedimentary rock? By knowing its history, we can interpret the age of the rock much better.‖ ―To understand the relative geologic history of a rock, Darrell uses thin sections because he’s interested in the relations a mong all the minerals, which make up the rock,‖ explains Mueller. ―However, for geochronology, we’re interested in the minerals that make u p one tenth o f one percent or less.‖ He looks at the zircon using various techniques —―light reflected off the grains, light transmitted through them, cathodoluminescent light resulting from hitting the zircon with an electron beam‖ —to establish the scale at which the zircon grains should be analyzed. Quantitative microanalysis of the elements in zircon is done with an electron microprobe. ―This allows us to analyz e things on a micron (a millionth of a meter) scale using a thin beam of electrons,‖ explains Henry. ―The electrons irradiate the sample, c ausing atoms within the sample itself to give off X -rays. Each of the atoms of the different elements in the sample gives off X -rays with characteristic wavelengths. You can then compare these to a standard with a known concentration of the element, and come up with an exact co mposition of that small spot. An individual zircon grain may be composed of many zones of different compositions and ages. Isotopic compos itions can be d etermined with an ion probe. Do we want to look at the whole grain, or should we direct a tiny beam of oxygen ions, 300 micr ometers in d iameter, on parts of the zircon grain to analyze for U (uranium) and Pb (lead) isotopes so we can date that spot and dissect the zircon’s individual history?‖ Alternatively, the uranium and lead can be separated chemically when an individual zircon grain is disso lved in h ydrofluoric acid. ―Then we analyze them on a mass spectrometer, which gives us the ratios of the individual uranium and lead isotopes, and from that we can calculate the time,‖ explains Mueller. Ultimately, says Henry, ―all of these data are combined into a larger picture of how the Earth worked billions of years of years ago.‖ In Mueller’s words, ―it boils down to the fact that the more we know about the variety of rocks that made up the earliest continents and how these continents evolved, the better our window onto how the Earth formed and the early processes that separated the crust from the mantle and probably even the mantle from the core.‖ Mueller describes his and Henry’s collaboration as a parallel journey. ―Our research marches down the same road, and sometimes we hold hands and sometimes we go our separate ways.‖ In either case, they’re constantly exchanging information yielded by their different approaches, and there’s always something new to look at. Mueller sums it up: ―One rock’s a lot of work.‖ Pasted from < file:///C: \Users\Brandon\AppData \Local\Temp\02i71ic7.tmp\Lesson%209%20Study%20Guide%20(Ch.9%20 -%20Geologic%20Time).doc > Geol 101 Page 290 Lesson10 Friday, June 03, 2011 10:03 AM Geol 101 Page 291 Geol 101 Page 292 Geol 101 Page 293 Geol 101 Page 294 Geol 101 Page 295 Geol 101 Page 296 Geol 101 Page 297 Geol 101 Page 298 Geol 101 Page 299 Geol 101 Page 300 Geol 101 Page 301 Geol 101 Page 302 Geol 101 Page 303 Geol 101 Page 304 Geol 101 Page 305 Geol 101 Page 306 Geol 101 Page 307 Geol 101 Page 308 Geol 101 Page 309 Geol 101 Page 310 Geol 101 Page 311 Geol 101 Page 312 Geol 101 Page 313 Geol 101 Page 314 Geol 101 Page 315 e xtension Geol 101 Page 316 Geol 101 Page 317 Geol 101 Page 318 Geol 101 Page 319 Guide Friday, June 03, 2011 10:03 AM GEOL 101 Lesson 10 Study Guide Chapter 12—Earthquakes In addition to your textbook, please use the websites and tutorials provided to you in the ―Suggested Websites‖ folder in Blackboard to help you answer these questions. Earthquake Mechanics (Sections 12.1 and 12.2) 1. What causes most earthquakes? 2. Define: Slip: amount of movement along a fault. distance the two rock bodies have been displaced Rupture Zone: the area of the fault that experienced movement Focus: Epicenter: 3. Explain (use logical reasoning to show cause and effect) the process of e lastic rebound. □ Rupture expands then snaps back together 4. What causes foreshocks ? a. represents the location where the stress is building 5. What causes aftershocks ? a. Rocks are adjusting and snapping back into place Earthquakes and Plate Tectonics (Section 12.4 and 12:5) 6. Where on Earth do most earthquakes occur? Plate boundaries 7. Focal depth: give the depth of the foci of the following earthquakes: Shallow focus: <50km Intermediate focus: 50- 300Km Deep focus: >300Km 8. At what type of plate boundary do you find most intermediate and deep focus earthquakes? Near trenches or Subduction zones 9. Explain why deep focus earthquakes occur at this kind of plate boundary but not at others. Because the cool plate is being subducted underneath another plate which allows for cool brittle deformation under the surface at deeper depths Go to the following Web site: . 10. Click on the map of the US. Where do most earthquakes occur in the US. Why? 11. ―Intraplate ‖ earthquakes occur inside of plates, away from tectonic boundaries. Do you see any on the map? What causes these intraplate earthquakes? Tennessee. these occur because of old fault zones Seismic Waves (Section 12.5) 12. What is the difference between a: Seismometer : Geol 101 Page 320 Seismogram: Below is a s eismogram that shows the arrival time of a seismic wave in seconds on the x- axis, and the amplitude of the wave over time. 13. What is the amplitude of the largest seismic wave shown in the diagram above? 14. What is the difference between body waves and s urface waves • Body Waves: (P&S) move through the earth □ Come in first • Surface Waves: Move on the surface of the earth □ Slowest Body Waves Explain and sketch the difference between how P- waves and S- waves travel through the Earth: P- Waves: Primary Waves come in first, they move horizontally making them faster S- Waves: Surface Waves come in second, up and down shearing motion 15. Which body waves (P- or S- ) have the greatest velocity? 16. Label the first arrival of the P- wave and S- wave on the seismogram shown above. 1st arrival of P- wave ______________ 1st arrival of S- wave ______________ 17. Compare the velocity of P- waves and S- waves when they travel through a liquid. Surface Waves 18. What is the difference between surface waves and body waves? Geol 101 Page 321 19. Notice the position of the surface waves in the seismogram above, as compared with the P- waves and SWaves (body waves). Which waves have the largest amplitude—P- , S- , or surface? 20. Notice the amplitude of the surface waves. Why do you think they are flat on top? 21. What is responsible for the low- amplitude ground motion that appears before the P- wave? Locating and Size of Earthquakes (Section 12.6) Travel-Time Curves Geol 101 Page 322 22. At any seismic station, we can determine the distance of an earthquake from the seismic station using a travel- time curve for the seismic station. Travel- time curves are developed at each seismic station by plotting the distance of a known earthquake from the past, and the first arrival times of the P- and Swaves of that earthquake. a. Look at the difference between the S- wave and the P- wave curves. What is the difference (in seconds) between the S- wave first arrival and the P- wave first arrival when an earthquake is at a distance of 100 KM away? _______________ seconds b. Notice the S- P curve. This is called the S-P lag time curve . It is just a plot of the difference between the first arrival of the S- wave and the first arrival of the P- wave. Use the S- P lag time curve to find the difference of the first arrival of the S - and P- wave when an earthquake is at 600 KM away from a seismic station ________________ seconds c. What do you notice about the difference between the first- arrival of the S- wave and the first arrival of the P- wave as the distance of the earthquake epicenters get further and further away? 23. The further away an earthquake is, the (larger, smaller) ___________ the S- P time interval. 24. Does the S- P lag time tell you the direction of the earthquake? Three Intersecting Circles Identify the Epicenter 25. The S-P lag time only tells you the radius from the seismic station to the earthquake. It does not tell you the direction to the earthquake. To get the direction, map the circles showing the distance to the epicenter from the seismic station. 26. Why can’t you use only two seismic stations to get the distance to the epicenter? 27. Circle the following information you must have to determine the location of an earthquake. a. Wave amplitude b. S- P time interval c. the type of rock the wave is traveling through d. the velocity of the seismic waves e. data from at least three seismic stations Richter Scale 28. What does the Richter Scale measure? a. Magnitude 29. Using the nomogram and seismograms below, answer the following questions: a. What is the magnitude of an earthquake if the amplitude of the seismic wave is 2 mm and the S - P Geol 101 Page 323 time interval is 10 seconds? b. The energy released during a magnitude 8 earthquake on the Richter scale is __________ times greater than that released during a magnitude 6 earthquake. Mercalli Scale 30. Compare the modified Mercalli Scale to the Richter scale. a. Mercalli scale measure the intensity of shaking (Roman Numerals from I- XII) it is a qualitative scale and the Richter scale is a quantitative measurement b. Scale based on human perception 31. Explain what a modified Mercalli intensity indicates. Used to map the orientation of the fault that created an earthquake 32. What factors influence the Mercalli intensity? Rock/subsurface composition – waves are amplified in softer less consolidated sediment Distance Away – farther away less the intensity Attenuation Magnitude Building construction Duration of Shaking Orientation of Faults- Earthquake Hazards (Section 12.7) 33. Describe how earthquakes can cause destruction, both during and after an earthquake: a. During: b. After: 34. List some ways to limit earthquake risk: 35. What should you do and should you not do during an earthquake? Geol 101 Page 324 Major North American Earthqakes (Section 12.8) 36. Be able to describe the causes and primary destruction that occurred during the following earthquakes: a. Alaska, 1964 1) Land slides 2) Fault Scarps 3) Tsunami b. San Francisco, 1906 c. Mexico City, 1985 d. Northridge, LA, 1994 1) Fire 2) Ground Shaking 3) Liquefaction a) Building began to sink into the ground e. New Madrid, 1811- 1812 f. Loma Prieta Earthquake (1989) Tsunamis (Section 12.10) 37. What are tsunamis and how are they generated? Earthquake Predictions (Section 12.12) 38. Explain why there is high earthquake risk in each of the red areas on the world map below. 39. There are 3 areas of the coterminous US, Alaska and Hawaii that have high earthquake hazard risks as shown on the map below. Describe the cause of earthquake risk in each of these areas. Geol 101 Page 325 Long Term vs Short Term Forcasting 40. What is long- term forecasting based on? 41. Explain how earthquakes can be predicted by using ―seismic gaps ‖, as shown in the cross- section below: 42. Explain what precursor events can be used for short- term earthquake prediction. 43. Describe the success of short- term earthquake prediction. Earth’s Interior (Section 12.15) 44. What is the difference between wave refraction and wave reflection? 45. Which way are seismic waves refracted when they enter a faster material - toward the boundary or away from the boundary? 46. Which way are seismic waves bent when they enter a slower material? Geol 101 Page 326 46. Which way are seismic waves bent when they enter a slower material? 47. In the figure below, label the top and bottom layers as ―slower‖ or ―faster‖ based on how the seismic ray is being refracted: 48. Explain why seismic waves take curved, rather than straight paths in the Earth? Use the diagram below to answer this question: 49. Using the diagram below, show the location and describe the P- and S- wave shadow zones. 50. Explain the causes of the P- and S- wave shadow zones. Place where you would not receive any seismic waves because the material in which they are able to travel through 51. How do we know the outer core is liquid? Pasted from <file:///C:\Users\Brandon\AppData \Local\Temp\fsq472qs.tmp\Lesson%2010%20Study%20Guide.doc> Geol 101 Page 327 Lesson 11 Monday, June 06, 2011 11:34 AM Geol 101 Page 328 Geol 101 Page 329 Geol 101 Page 330 Geol 101 Page 331 Geol 101 Page 332 Geol 101 Page 333 Geol 101 Page 334 Geol 101 Page 335 Geol 101 Page 336 Geol 101 Page 337 Geol 101 Page 338 Geol 101 Page 339 Geol 101 Page 340 Geol 101 Page 341 Geol 101 Page 342 Geol 101 Page 343 Geol 101 Page 344 Geol 101 Page 345 Geol 101 Page 346 Geol 101 Page 347 Geol 101 Page 348 Geol 101 Page 349 Geol 101 Page 350 Geol 101 Page 351 Geol 101 Page 352 Geol 101 Page 353 Geol 101 Page 354 Geol 101 Page 355 Geol 101 Page 356 Geol 101 Page 357 Geol 101 Page 358 Geol 101 Page 359 Geol 101 Page 360 Geol 101 Page 361 Geol 101 Page 362 Geol 101 Page 363 Guide Monday, June 06, 2011 11:34 AM GEOL 101 Lesson 11 Study Guide Chapter 16—Rivers and Flooding River Systems (Section 16.1) North Carolina’s Drainage Basins Rivers in North Carolina receive their water from the areas they drain – their drainage basins . The basins are drained by tributaries (streams, creeks), which flow to the main, larger river. The hydrograph above shows rainfall of a creek, in inches, during each 15- minute increment of a storm. It also shows the streamflow (discharge ) of the creek, in cubic feet per second (ft3 /s). Peak rainfall or peak streamflow refers to the maximum values on this chart. 1. Discharge: Q = AV where: Q = discharge, usually in ft3 /sec or m3 /sec A = (D x W)cross- sectional area of the stream, usually in ft2 or m2 V = velocity of the water, usually in ft/sec or m/sec Calculate the discharge for the following river channel: Discharge = 4X5=20 20 X1=20 ft3 /sec Geol 101 Page 364 2. Lag Time Using the hydrograph above, compare the peak rainfall to the peak streamflow. This is called lag time . a. What are the values for peak rainfall and peak stream flow on the graph? b. Label the difference between peak rainfall and peak streamflow (lag time interval) on the hydrograph. c. This lag time is due to infiltration of water into the ground before it hits the stream. Explain how infiltration can cause the lag time between the peak rainfall and peak runoff. 3. Rates and Amounts of Runoff The amount and rate of runoff is controlled by many factors. Define each factor listed below, and then explain how the amount and rate of runoff would change if the factor increased or decreased: Factor Affecting Runoff Define Explanation Precipitation (Climate ) Long term temp and precipitation patterns Drainage Basin Area and Shape The whole area that is a hydrograph for a simple basin shows a drained by a river and its single peak increase in discharge with a tributaries. influence its gradual decrease in contrast a complex three flow response to rainfall part drainage basin may show a three peak response to a single event. Total discharge in a larger basin will be higher and more spread out because some water travels short distances and other water travels long distances Basin Slope (Gradient) Overall slope of a drainage basin helps determine how fast water in the basin empties after a heavy rain or after snowmelt Runoff from a steep drainage basin is fast and much water arrives downstream at about the same time yielding higher discharge value…. Runoff from more gntly sloped basin is spread out over time leading to a lower peak discharge Erosion, deposition and sediment load in rivers (Sections 16.2 and 16.3) 4. Observe how sediment is transported in the following animation: chapter_no=13 Then, on the diagram below: a. Label where you would find clay, silt, sand, and gravel being deposited in an average- flowing stream. Geol 101 Page 365 a. Define: Bedload ◊ Material that is pushed bounced rolled and slid along the bed of the river Saltation: ◊ sand grains roll along the bottom or be picked up and carried down- current by bouncing along the streambed. Suspended load: ◊ Fine particles can be carried suspended in the moving water even in a relatively slow current the material is the Suspended Load Dissolved load: ◊ Some Chemically soluble ions such as calcium and sodium are dissolved in and transported by the moving water. they constitute the dissolved load 5. Define turbulent flow, and explain how it can cause erosion. You can view the following animation for help: Turbulent Flow: is rough waters caused by steep gradients (slope) high energy low velocity Laminar Flow: Smooth Flow gentle gradient(slope) Low energy high velocity chapter_no=13 6. What is the relationship between velocity and the type of sediment that can be transported in a river? (page 471, Section 16.3). As the water velocity increases the flow becomes more chaotic or turbulent and the water can pick up and move material within the channel 7. What causes deposition? View the following animation for help: chapter_no=visualization Deposition occur where the water velocity decreases, for example along the river banks during flooding or in pools behind rocks or other obstacles. Rocks and sediment constrict this river, forming a lent water upstream. During floods sediment is deposited in slow- moving eddies on the flanks of this pool but such sediment is vulnerable to later erosion and is therefore very transient How streams change downstream (Sections 16.4, 16.10, 16.11) Use the following diagram and your textbook to answer the following question: Geol 101 Page 366 8. Define the following factors and explain what happens to these factors as you go from a river’s headwaters to its base level: c. Gradient: is the change In elevation /(distance) d. Maximum sediment grain size: e. Total sediment load: f. Channel size: g. Water velocity: increases h. Discharge: 9. Explain what a delta is and how it forms (Section 16.9). Here are some pictures of the Mississippi River delta: 10. Explain why a stream might incise if base level falls. Draw a cross- section showing how this happens. 11. Explain how a stream will deposit sediment if base level rises. Draw a cross- section showing how this happens. 12. What could cause base level to fall? 13. Give one example of a fall in base level in the past. 14. What could cause base level to rise? 15. Explain why the Grand Canyon is incising into the Colorado Plateau (Hint: View the Virtual Tour of the Grand Canyon website). Geol 101 Page 367 River Morphology (Sections 16.5 – 16.8) 16. What is an alluvial fan? Where do you find them? How and why do they form? 17. Draw a cross- section of a river showing a channel, point bar, natural levee, flood plain, and edges of the river valley. 18. Among the elements shown above, where would you find the largest quantity of: a. Sand: b. Gravel: c. Silt and Clay: 19. How do meandering rivers form? 20. Draw a map- view of a meandering stream showing a cut bank, point bar, and oxbow lake . 21. What is an oxbow lake and how does it form? Draw a diagram showing how an oxbow lake forms. 22. Draw a map- view of a braided stream showing channels and longitudinal bars 23. Compare (list similarities and differences) meandering and braided streams. Floods (Section 16.12) 24. What is a flood? Predicting Floods Use the flood frequency curve below to answer the following questions: 25. About how often can you expect a flood that has a discharge of 100,000 ft3 /sec? 26. What is the approximate discharge of the 100- year flood? 27. What is the probability that the 100- year flood will occur this year? Exeedance probability = 1/Recurrence Interval Geol 101 Page 368 Infiltration and Urban Flooding 28. Analyze the hydrographs above. Note on the graph which hydrograph is for an urban area, and which hydrograph shows the rural stream. 29. Which type of land (urbanized or rural) results in a higher peak discharge more quickly? Why do you think this happens? 30. So how does land surface affect rates of infiltration? 31. If you were a city planner whose community was rapidly becoming urbanized, what would you do to preserve infiltration rates and increase lag times during high rates of rain fall? Geol 101 Page 369 Pasted from <file:///C:\Users\Brandon\AppData\Local\Temp\b1ytlnvb.tmp\Lesson%2011%20Study%20Guide.doc> Geol 101 Page 370 Lesson 12 Wednesday, June 08, 2011 10:59 AM Geol 101 Page 371 Geol 101 Page 372 Geol 101 Page 373 Geol 101 Page 374 Geol 101 Page 375 Geol 101 Page 376 Geol 101 Page 377 Geol 101 Page 378 Geol 101 Page 379 Geol 101 Page 380 Geol 101 Page 381 Geol 101 Page 382 Geol 101 Page 383 Geol 101 Page 384 Geol 101 Page 385 Geol 101 Page 386 Geol 101 Page 387 Geol 101 Page 388 Geol 101 Page 389 Geol 101 Page 390 Geol 101 Page 391 Geol 101 Page 392 Geol 101 Page 393 Geol 101 Page 394 Geol 101 Page 395 Geol 101 Page 396 Wednesday, June 08, 2011 10:59 AM Guide Lesson 12 Chapter 17—Groundwater In addition to your textbook, please go to the ―Suggested Websites‖ section of Blackboard to view tutorials that will be helpful with answering the questions below. Hydrologic Cycle – USGS Web site (or Section 17.1 in textbook) Reservoirs How does water move from and to this reservoir? % of Fresh Water 96.5% Oceans % of Total Water on Earth 3.5% Ice Caps and Glaciers Groundwater Freshwater (lakes, swamps, rivers) Define and explain the following: Water Movement Processes Definition Evaporation Condensation Precipitation Runoff Infiltration Springs (and groundwater discharge) Evapotranspiration Freshwater Usage (Section 17.2) 1. Rank the following freshwater users by re- writing the list below, with the greatest water users at the top and the least water users at the bottom: Public and domestic use Industrial use Irrigation Thermoelectric power Groundwater Basics (Section 17.3) 2. Define the following ways groundwater occurs: a. Pore space: b. Fractures: c. Caves: Geol 101 Page 397 3. Define and compare the following terms: a. Unsaturated Zone: zone were all pores are not completely filled with water and is synonymous with the zone of aeration b. Saturated Zone: is the zone were all the pores are filled with water c. Water Table: the area that separates the saturated zone and the unsaturated zone Porosity and Permeability (Section 17.3) 3. Define the following and explain how they control the ground water flow through earth materials: a. Porosity: i. Definition: ii. Materials that have high porosity: iii. Materials that have low porosity: iv. How to calculate porosity: Porosity = Total volume of pore space in a rock X 100 Total volume of rock 4. Calculate the porosity of the sand shown in the picture below: Geol 101 Page 398 a. Sorting: i. Definition: ii. Explain the difference in texture (distribution of grain sizes) between poorly sorted and well sorted clastic sediment and clastic sedimentary rocks. iii. Give one example each of a typically well sorted and a poorly sorted clastic sedimentary rock. iv. Explain the difference in porosity between poorly sorted and well sorted sedimentary rocks. 5. Permeability: i. Definition: ii. Which of the following shows the units of permeability? (Circle the best answer) a. % b. ft3/sec c. ft/sec d. ft iii. In general, materials with high porosity have high permeability. Exceptions are shown below. Explain why the following materials could have high porosity but low permeability: 1. clay: 2. vesicular volcanic rocks: 6. Different factors within rocks can change the porosity and permeability of a rock. Answer the question below: Factor Explain what will happen to porosity and permeability (will they be high or low?) when the factor is increased or decreased. Cement between sedimentary grains Increase cement Down Write down the effect on porosity and perm: Up Write down the effect on porosity and perm: Decrease cement: Fractures Increase fractures: Up Geol 101 Page 399 Write down the effect on Fractures Increase fractures: Write down the effect on porosity and perm: Decrease fractures: Sorting Up Down Write down the effect on porosity and perm: Increase sorting: Write down the effect on porosity and perm: UP Decrease sorting: Write down the effect on porosity and perm: Down Compaction (depth) Increase compaction: Write down the effect on porosity and perm: Down Decrease compaction: Up Write down the effect on porosity and perm: 7. Porosity and Permeability of Rocks are one of the main controls on ground water flow. Different rocks have different porosities and permeabilities. Answer the question for each rock type given in the table below: Material or Rock Type Explain whether the porosity and permeability of the indicated rock type is high or low and explain why it is high or low. Loosely cemented gravel and sand Unfractured Igneous and Metamorphic Rocks (commonly referred to as ―Crystalline Rocks‖) Conglomerate Shale Limestone Groundwater Flow (Section 17.4) 8. The water table generally slopes from ___High to Low areas. a. Flows from high pressure to low pressure and then flow straight up then out Geol 101 Page 400 9. Lakes, wetlands, springs and streams can all form when: 10. The rate of ground water flow is strongly controlled by: 11. Define the following: a. Ground water divide: Place where ground water flows different direction depending on where the water divide is. Similar to drainage basin divide b. Hydraulic gradient: the slope of the groundwater flow. the higher the gradient the faster ground water flows Aquifers (Section 17.4) 12. Define the term ―aquifer‖ and explain what types of materials make a good aquifer. Aquifer is a geologic formation that can store significant quantities of water that can supply the public good Good ones are well sorted or gravel and Sand (sediment) conglomerate or sandstone that doesn’t have a lot of cement. Fractured rock (like fractured granite) Limestone- Calcite. 13. Define: a. Impermeable layer: b. Confining layer: a layer of low permeability c. Perched water: Perched aquifer is underlain by low- permeability unit one that is above main aquifer d. Artesian Wells and Water: water rises in pipe (maybe to surface) 14. Draw a diagram showing the difference between an unconfined aquifer and a confined aquifer. 15. In words, compare unconfined and confined aquifers: Unconfined Confined Open to the earths surface and to infiltration 16. View the ―Groundwater in the Piedmont‖ website in the ―Suggested Websites‖ folder for Lesson 12 in Blackboard. Then, answer the following question: Describe the type of aquifer you would expect to find if you drilled for water in the NC Piedmont. 17. Why can a well be ―artesian‖ if it is drilled in a confined aquifer but will not be artesian if it is drilled in an unconfined aquifer? 18. What type of aquifer do you think would be safest from surface contamination? Why? Groundwater – Surface Water Connections (Section 17.5) Geol 101 Page 401 Go through the ―Groundwater Tutorial II‖ in the ―Suggested Websites‖ folder in for Lesson 12 in Blackboard. Then, answer the following question: 19. In an unconfined aquifer, at what time of year is the water table highest? Lowest? 20. Groundwater and surface water are connected. Define the following as they relate to ground water: a. Recharge: b. Discharge: where water table intersects surface water can flow out 21. Define the following and explain how each can form: a. Spring b. Geyser: c. Hot Spring d. Gaining Stream: e. Losing Stream: stream is losing its water to the ground and replenishing the ground water f. Karst topography: g. Stalactite (―hang tight from the roof‖): h. Stalagmite (mounds- up from the bottom): i. Travertine Karst Topography (Section 17.6) Use your textbook and the ―Karst Websites‖ in your Lesson 12 ―Suggested Websites‖ folder on Blackboard to answer the following questions. 22. What type of rock does karst terrain form in? 23. Provide the chemical equation that dissolves the rock in karst terrain (hint: think back to Ch. 15 when you learned about dissolution of calcite). Geol 101 Page 402 24. Describe how each of the following karst features form: Sinkhole: Depicting the Water Table and Ground Water Flow (Section 17.7) 25. The map above shows ground water elevations in monitoring wells. Using a 10- food contour interval, draw a contour map of the water table, and then indicate the direction of ground water flow. (Note: DO NOT ―connect the dots‖ – interpolate between the points). If you need help with contouring, please see the ―Contouring Video‖ in the ―Suggested Websites‖ Lesson 12 folder in Blackboard. Groundwater Problems: Pumping (Section 17.8) 26. Define the following terms, explain how they form and why they can be a problem to surrounding areas: a. Cone of Depression: b. Compaction, Subsidence and Fissures: c. Saltwater Incursion: Water Problems: Contamination (Section 17.9) 27. Describe how the following sources can contaminate surface and groundwater: a. Weathering of rocks: b. Petroleum and coal: c. Landfills: d. Human waste: e. Farms, ranches and commercial orchards: f. Gas stations: g. Manufacturing facilities: h. Dry cleaners Geol 101 Page 403 h. Dry cleaners 28. The procedure to correct ground water problems is tackled in three main ways. Explain how you would accomplish each step below: a. Determining the direction of ground- water flow; b. Determine concentration of contamination in groundwater; c. Remediation Pasted from <file:///C:\Users\Brandon\AppData\Local\Temp\2bqcatwy.tmp\Lesson%2012%20Study%20Guide_1.doc> Geol 101 Page 404 Lesson 13 Friday, June 10, 2011 11:04 AM Geol 101 Page 405 Geol 101 Page 406 Geol 101 Page 407 Geol 101 Page 408 Geol 101 Page 409 Geol 101 Page 410 Geol 101 Page 411 Geol 101 Page 412 Geol 101 Page 413 Geol 101 Page 414 Geol 101 Page 415 Geol 101 Page 416 Geol 101 Page 417 Geol 101 Page 418 Geol 101 Page 419 Geol 101 Page 420 Geol 101 Page 421 Geol 101 Page 422 Geol 101 Page 423 Geol 101 Page 424 Geol 101 Page 425 Geol 101 Page 426 Geol 101 Page 427 Geol 101 Page 428 Guide Friday, June 10, 2011 11:04 AM GEOL 101 Lesson 13 Study Guide Chapter 14—Shorelines, Glaciers, and Sea-Level Change In addition to your textbook, there are good animations and tutorials describing some of the processes in this study guide. Shoreline Processes – Ch.14.1 1. Explain the processes that shape shorelines and describe how they effect the coastline: Process Definition/ Description of processes Waves form from the movement of the wind Tides form from the moons gravity and the gravitational pull of the ocean Climate, Rivers and Deltas Wind Faulting and Plate Tectonics Sea level change Tides – Ch.14.2 2. What are tides, and what causes them? 3. Sketch and summarize how the gravity of the moon and Sun cause s pring and neap tides. Waves and Longshore Currents Ch.14.3 and 14.4 4. What causes ocean waves? 5. Sketch and label the parts of a wave, including the height, wavelength and wave base. 6. Breakers: Explain why a wave rises and breaks as it reaches shallow water. Geol 101 Page 429 7. Wave Refraction: Explain what wave refraction is and why it happens at a coastline. 8. Explain what happens when waves refract around a headland. 9. Longshore Currents: Explain what a longshore current is and how it forms 10. Longshore Drift: Explain what longshore drift is and how it moves along the shoreline 11. What are the main sources of sediment on a coast? a. rivers 12. What are the main ways sand moves at the coast? 13. Why is beach sand typically quartz- rich? Coastal Landforms – Ch14.5 14. Differentiate between erosional and depositional features on shorelines and explain how each forms Erosional Features Depositional Features Headlands Sand bars – Sea Cliffs – Barrier Islands – Caves and Sea Arches – Spits – Sea Stacks – Baymouth bars – Wave- cut platforms - Shoreline Protection – 14.6 15. Describe the positives and negatives of some of the ways humans have tried to control shoreline erosion. In addition to your textbook, the following website has a tutorial and simulation that may help: Control Measure Pros Cons Groins Jetties Deposit Sediment Breakwaters Sea Walls Geol 101 Page 430 They casue Sediment to erode form some place else Beach Nourishment • way to put sand back on beaches • Take sand from somewhere else and bring it to the beach 16. Based on where the sediment is building up in the photo, which way is the long shore current is going (ie- left to right, top to bottom, right to left, etc.)? Sea-level Changes and Coastlines – Ch.14.8 and 14.9 17. Compare the factors that would cause coastlines to be s ubmergent rather than e mergent. 18. Differentiate the characteristics of s ubmergent verses e mergent coastlines. a. Submergent 1) NC a) Subsidence of the continental margin due to increasing density of ocean crust as it leaves as it spreads away from the mid Atlantic ridge 2) Sea level is rising due to global warming - > ice caps melting 3) Sediment supply is decreasing because of damming the rivers and the sediments being held. b. Emergent i. Rock Uplift 1) CA- Tectonic 2) Maine- Isostatic Rebound ii. Lower Sea Level 1) Build the ice caps (glaciations) 19. Describe the factors that can cause sea- level change: Glaciation: Geol 101 Page 431 Glaciation: Rate of Sea- floor spreading: □ when the rates are high the sea floor will rise and when the sea floor goes up the water is displaced and the coastlines flood and cause transgressions Ocean Temperature: □ When temperature goes up the volume of water goes up causing the sea level to rise Polar verses equatorial position of continents: Loading and isostatic rebound of the crust: * HEADLAND = Promontory Pasted from <file:///C:\Users\Brandon\AppData\Local\Temp\p9dr8trd.tmp\Lesson%2013%20Study%20Guide%20Ch.14Shorelines.doc> Geol 101 Page 432 ...
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Geol 101 - Syllabus W ednesday, May 11, 2011 11:52 AM GE0L...

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