S e d i m e n t a r y R o c k s

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3. 3 Sedimentary Rocks Rocks � Weathering to sediment � Transport (Water, Wind, Waves & Ice) � Deposition of sediment � Diagenesis

4. 4 Physical, chemical & biological changes Recrystallization (less stable to more stable) Aragonite to Calcite Lithification Compaction & Cementation Common cements - Calcite, Silica & Iron Oxides

5. 5 75% of all rock outcrops on the continental crust Yet, only 5% by volume of Earth�s outer crust

6. 6 Contain clues/evidence of past events Contain fossils Aid in reconstructing geologic history Economically important Coal, Oil, Natural Gas, Groundwater, Aluminum, Manganese

7. 7 Detrital Sedimentary Rocks From solid particles of mechanical & chemical weathering Chemical Sedimentary Rocks From dissolved materials of chemical weathering

8. 8 Detrital Rocks Predominantly Contain: Clay minerals Quartz Feldspars & Micas

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10. 10 Grain size indicates energy of the transporting medium & of the depositional environment Larger grains indicate higher energy

11. 11 Shale Siltstone Sandstone Conglomerate/Breccia

12. 12 Very fine grained (clay particles) Layered Not well cemented > Half of all sedimentary rocks, but does not form prominent outcrops

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15. 15 Second most abundant sedimentary rock 20% of all sedimentary rocks Can see the grains with unaided eye Sorting How similar the size of grains are Wind sorts better than water Waves sort better than stream flow

16. 16 SS predominantly quartz = Quartz SS when referring to ss, we generally mean this SS with at least 25% feldspars = Arkose SS with quartz, feldspars, rock fragments and mud = Graywacke

17. 17 Predominantly gravels, sand & mud Poorly sorted (many grain sizes) Grains are rounded Mountain streams / strong wave action

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19. 19 Also predominantly of gravels, sand & mud Poorly sorted Large particles are angular Mountain streams / strong wave action

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21. 21 Chemical sediments derive from material carried in solution. Mineral matter precipitates by Inorganic processes (evaporation) Organic (biochemical) processes (water-dwelling organisms cause the precipitation)

22. 22 Limestone Dolostone Chert

23. 23 10% of all sedimentary rocks Most abundant chemical sed. rock Consists mostly of calcite Both inorganic and biochemical origin Marine biochemical origin most common

24. 24 Coral Reefs Coquina Chalk Inorganic limestones Travertine Oolitic limestone Amongst others

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29. 29 Consists of the mineral dolomite Dolomite is a calcium-magnesium carbonate Very similar in composition to limestone Origin is not certain

30. 30 Made of microcrystalline silica (SiO2) Skeletons of Diatoms & Radiolarians, some sponges �Varieties� Flint (contains organic matter, usually dark in color) Jasper (red in color from iron oxide) Agate (banded) (the book included it � agate generally forms from dissolved silica in other rocks)

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32. 32 From evaporation of sea water or groundwater Halite (NaCl) Common Table Salt Gypsum (CaSO4.2H2O) Plaster of Paris, Gypsum wallboards

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34. 34 Looking at it a different way: From a 1000-ft column of sea water, you will get: 1.2 inches of calcite 7 inches of gypsum 13 feet of halite 3 feet of potassium & magnesium salts

35. 35 There are beds of salt hundreds of feet thick Think of how much water needs to be evaporated to produce them

36. 36 Coal is made from organic matter Begins to form in bogs/swamps from dead plant matter Very important energy source Plentiful & Cheap Pollution due to sulfur compounds

37. 37 Organic matter is buried in swamps Swamp water is O2-deficient Bacteria partly decomposes organic matter O2 & H2 are released & Carbon accumulates Bacteria dies off, resulting in Peat Higher temps. cause further chemical reactions

38. 38 Detrital (Grain Size) Coarse (>2mm) Medium (1/16 - 2 mm) Fine (1/256 - 1/16 mm) Very Fine (< 1/256 mm)

39. 39 Clastic Broken fragments cemented together All detrital & some chemical rocks Non-clastic or Crystalline Minerals form a pattern of interlocking crystals, may resemble igneous rock All are chemical rocks

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41. 41 Beaches Spits Sand dunes

42. 42 Continental Marine Transitional (Shoreline)

43. 43 Erosion & deposition are influenced by local climate Streams (fluvial deposits) Most common & most dominant Stream channel, floodplain Glacial High Altitudes / Latitudes these days Wind (eolian or aeolian deposits) Arid regions

44. 44 Shallow Marine Less than 200 m deep From the shore to the edge of the continental shelf Deep Marine Deeper than 200 m

45. 45 Shallow Marine Average width 80 km around continental margins Receives a large amount of land-derived sediment Carbonate-rich mud a predominant sediment if little land-derived sediment Coral reefs in warm waters (tropics)

46. 46 The floors of the deep ocean Fine-grained particles Slow deposition

47. 47 Beaches Tidal flats Spits

48. 48 Facies - describes sets of lateral sediments (going in a line from the shore to the deeper water) with distinct characteristics that indicate their depositional environments

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50. 50 Strata or beds Most important, common, characteristic feature of sedimentary rocks Usually based on the texture & composition Strata are separated by �bedding planes�

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52. 52 Cross bedding sand dunes & river deltas

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54. 54 Graded bedding coarse to fine (most common) rarely fine to coarse

55. 55 Ripple marks By the action of moving water or air The ridges form at right angles to the direction Symmetric and asymmetric Fossils Evidence of former life

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58. 58 Mud cracks

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