Lecture-13-F10 - EAS 111 General Announcements • Schedule...

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Unformatted text preview: EAS 111 General Announcements 10/18/10 • Schedule Reminder This week (10/18 & 10/20) – Mon 10/18 Sedimentary Processes and Rocks, Part 2 – Weds 10/20 Geologic Time, Part 1 – Bring your text for lab this week! The week after that (10/25 & 10/27) and beyond – Mon 10/25 – Geologic Time, Part 2 – Weds 10/27 – Review for Lab Exam 2 and Lecture Exam 2 – Monday 11/1 = EXAM 2 – Lab Exams run from Tues 11/2 through Friday 11/5 Earth and Atmospheric Sciences 111 Fall 2010 Sedimentary Processes & Rocks II -Sedimentary Environments -Sedimentary Rocks - Using the rock record to understand change through time -Fossil fuels 101 Lecture 13 Observe the range of clast Observe size (sorting) in each photograph photograph Moderately sorted Poorly sorted 07.04.a Well sorted Observe the shape of Observe these clasts these Partially rounded Angular 07.04.a Rounded Controls on Size, Shape, and Sorting Farther from source means rounder and smaller Steepness of Steepness slope slope Strength of current Agent of transport 07.04.b How Clastic Sediment Becomes Rock Compaction of Compaction sand grains sand Compaction of Compaction clay particles clay Cementation - calcium carbonate calcium (calcite) (calcite) - silica (quartz) silica - iron oxides iron 07.05.a Indicators of Environment Color of rocks Size, shape, sorting Thickness of bedding Type of bedding Mudcracks Fossils 07.13.a Clast Sizes Sand: Coarse, medium, fine Boulders, cobbles, Boulders, pebbles pebbles Clay and silt 07.04.a Common Clastic Sedimentary Rocks Largest dominant clast size is gravel Largest dominant clast size is gravel and is very angular Conglomerate Largest dominant clast size is sand Breccia Largest dominant clast size is clay 07.05.b Sandstone Shale CPS: Based on this rock type, the depositional environment is likely… depositional Shale A. near to the sediment source area B. a high-current, high energy place C. a low-current, low energy place D. not possible to deduce based on this information Observe these environments and their sediment sediment Glacier Glacier Mountains Steep stream Steep or river or 07.01.a Sand dunes Observe these environments Observe and their sediment sediment Gentle, Gentle, meandering river river Delta Delta 07.01.a Wetlands Lake Observe these environments Observe and their sediment sediment Coastal Coastal dunes dunes Beach 07.02.a Lagoon Reef CPS: What kind of environment would NOT likely form a conglomerate? NOT A. Ocean beach with cliffs A. Mountain river A. Deep sea A. Glaciers Conglomerate Carbonate Rocks and Their Environments Limestone Limestone w/ fossils Dolostone Carbonate Rocks in Landscape Limestone Limestone Soluble limestone Dissolved Dissolved 07.11.d •Biogenic rocks •Made by the metabolic action of living things •Low clastic sediment input •Usually shallow, warm marine conditions •Rarely freshwater Lagoon Reef 07.02.a Studying History of Sedimentary Rocks Present key to past Past environments Past climate Past events Sequence of events Ancient life 07.14.b Time 1 Beach sand Observe what happens Observe when seas move in when Time 2 Mud over Mud sand sand Limestone Mudstone Sandstone Older units Section Section formed during a transgression transgression 07.12.a Time 3 Reef Limestone Limestone over mud over Time 3 CPS: Between Time 3 and 4 the sea moved OUT again. What rock type would likely be deposited next in the sequence shown below? A. B. C. D. ? Limestone Mudstone Sandstone Older units Older Time 4? Sandstone Breccia Mudstone Granite Resources in Sedimentary Rocks Groundwater Petroleum Coal How are these formed? Where are they found? How do we get this out of the ground? Cement from Cement limestone limestone Salt Uranium 07.14.a Where Petroleum Comes From Where 18.01.a-b Reefs Plants Microorganisms Accumulation of Accumulation organic material organic Buried and Buried preserved in oxygen-poor conditions conditions Buried and Buried heated to right temp. right How Folded Layers Trap Oil and Gas How Most anticlines Most shaped like “A” shaped Trapped in anticline below Trapped impermeable layer (cap rock) impermeable Oil and gas Oil migrate up flanks of anticline anticline 18.02.a1 In pore spaces between grains and along In bedding planes and fractures in reservoir rock reservoir How Salt Domes Trap Oil and Gas Petroleum trapped in top of dome Rocks above salt Rocks dome are bowed up up Oil and gas Oil trapped on sides of impermeable dome dome Salt flows up as a weak mass 18.02.b1 Observe petroleum basins in the U.S. 18.02.c5 Observe where oil shale is found in the U.S. Oil shale 18.04.c Observe the location of the world’s largest deposits of Observe tar sands tar 18.04.d2 Observe how coal forms 18.03.a Peat Lignite Bituminous Bituminous coal coal Plant matter gets buried Plant and heated into better coal and Anthracite How Coal is Mined, Transported, and Used Power plant Coal stockpiles Strip mine ine m p tr i S Reclaimed land land 18.03.b Underground mine Observe where coal and coal-bed methane occur Methane Methane collection tanks collection 18.04.a EAS 111: Assignments for 10/20/10 • Exploring Geology • 8.13 parts A and B - putting it all together to establish time-lines of events • 9.1, 9.3, 9.4, 9.5, 9.6, 9.7, 9.8 • The basics of geologic dating – sequences of events and correlation of events at remote locations ...
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  • Spring '10
  • Dr.EricRiggs
  • Sedimentary rocks, clastic sedimentary rocks, limestone limestone, Reef Limestone Limestone, dominant clast size

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