112lect1 - GY 112 Lecture Notes D Haywick(2006 1 GY 112...

Info icon This preview shows pages 1–3. Sign up to view the full content.

View Full Document Right Arrow Icon
GY 112 Lecture Notes D. Haywick (2006) 1 GY 112 Lecture Notes Rock Review Lecture Goals : A) Recap of rock types B) Recap of the rock cycle C) Sedimentary rocks: their role in earth history Textbook reference: Levin 7 th edition (2003), Chapter 2 ; Levin 8 th edition (2006), Chapter 4 (For those of you who have already completed GY 111, you will find your lecture and lab notes of use for this part of GY 112) A) Recap of rock types To cut to the chase, there are 3 main divisions of rocks, but in GY 112, the sedimentary rocks are by far the most important. The reason? They are commonly fossiliferous (meaning that they host fossils). First off, here are the 3 main rock divisions: Igneous (formed from molten rock) Sedimentary (formed from particulate material) Metamorphic (alteration of parent rocks through heat, pressure and fluids) Each of these rock groups have subdivisions. As I said earlier, it is the sedimentary rocks that are the most important group in GY 112. Let’s start with them: Sedimentary rocks are classified according to two different parameters: 1) Grain size (see chart to left) and composition . The grain size refers to the size of the particles that make up the rocks. These are the “things” that were initially deposited before the sediment became “ lithified” , which just means conversion into “rock”. There are 4 major size divisions of sediment that you need to remember: 1) gravel (the largest division; grains 2.0 mm), 2) sand (grains <2.00 mm but 0.63 mm), 3) silt (grains <0.63 mm but 0.004 mm) and clay (grains 0.004 mm). Obviously, you can’t see the really small silt and clay grains. Sedimentologists (those really cool and wonderful scientists like Dr. Haywick that study sedimentary rocks), frequently have to use microscopes and scanning electron microscopes to study the smallest sedimentary particles.
Image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
GY 112 Lecture Notes D. Haywick (2006) 2 As far as composition is concerned, sedimentary rocks are classified into four sub- divisions: 1) Clastic (also known as siliciclastic); rocks contained particles rich in silica-rich minerals such as quartz, feldspar and clay minerals. Examples include quartz arenite 1 sandstone, arkose sandstone, greywacke sandstone, shale, claystone, siltstone and mudstone. 2) Bioclastic; rocks containing remains of once living creatures (aka beasties). Examples include limestone (carbonate shells and skeletal elements), chalk (microscopic carbonate shells and body parts) and biogenic chert (microscopic silica body parts).
Image of page 2
Image of page 3
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

What students are saying

  • Left Quote Icon

    As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

    Student Picture

    Kiran Temple University Fox School of Business ‘17, Course Hero Intern

  • Left Quote Icon

    I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

    Student Picture

    Dana University of Pennsylvania ‘17, Course Hero Intern

  • Left Quote Icon

    The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

    Student Picture

    Jill Tulane University ‘16, Course Hero Intern