The Rock Cycle and Soils

1. The Rock Cycle and Soils Chapter 4 Addendum

2. What is a Rock? • Solid mass of minerals or mineral–like matter

3. 1. Three types of rocks: a. Igneous Rock (from “ignis” in Latin, meaning fire) b. Rock begins as liquid (magma) beneath the earth’s surface, and form when magma/lava cool and hardens.

4. Igneous rock begins as magma.

5. (1) Rocks that forms from lava (magma on earth’s surface) are extrusive.

6. (a) Rocks that form from magma cooled under the surface are intrusive http://geology.com/

8. How are magma & lava the same, and how are they different? • Same • Both terms used to describe molten rock • Composition can be the same • Different • Magma is melted material beneath the Earth’s surface • Lava is melted material at the Earth’s surface

9. b. Sedimentary Rocks (1) Form when sediments become compacted and cemented together. They are called clastic sedimentary rocks.

12. Explain Compaction & Cementaion Compaction- process that squeezes sediments together Cementation- occurs when dissolved minerals are deposited/distributed in the tiny spaces among sediments

13. Or (2) Compounds are chemically bonded to form rocks. They are called chemical sedimentary rocks.

14. Rock Salt

15. Salt flats in Turkey

16. Salt Flats Boneville, Utah

17. Gypsum

19. Or (3) Compounds are passed through, or used by an organism then form rock. They are called organic sedimentary rocks.

20. coal

21. Sedimentary rocks are a result of… Weathering Erosion and deposition Compaction and Cementation

22. c. Metamorphic rock (“meta meaning change, “morph” meaning form)

23. (1). Formed when chemical reactions, heat, pressure, radioactive decay or friction change existing rock into a rock with different chemical and physical properties.

24. (2)Temperatures increase and the rock becomes flexible (not melting). The atoms rearrange themselves to more heat tolerant materials become denser (more atoms per unit area).

25. Marble

26. Slate

27. Gneiss

28. (3) Rockscan undergo metamorphism (change) two main ways

29. (a) Contact metamorphism- when rock comes into contact with magma in the ground and the heat from the magma will change the composition of the rock and creating a new metamorphic rock

30. (b)Regional Metamorphism- when enormous pressure builds up in rock, that is buried underground and the temperature increases (due to the pressure). This extreme pressure and heat causes the rock to become deformed and chemically changed forming new metamorphic rock

31. 2. Recyling Rock a. Earth is very dynamic – changes occurring all the time. (Ex. Movement of tectonic plates, volcanoes, mountain formation, weathering) which affect rock composition, size, shape, and location.

34. b. There is no definite sequence to the process.

35. c. Major factors that cause change: temperature, pressure,friction, weathering, time, and composition of rock.

36. Example of Rock Cycle: (tables in text pages 74, 79, and 84) Granite ­­weathering to clay­­> particles travel down stream –­settling­­> into layers ­­cementation­­> sedimentary (shale) ­–heat and pressure ­­> metamorphic (slate) ­­where could it go from here?

37. Example of Rock Cycle: Shells containing Calcite (CaCO3) ­­weathering to calcite particles­­> particles settling on sea floor into layers ­­> cementation and compaction­­> sedimentary (Chalk, Limestone) ­–heat and pressure ­­> metamorphic (Marble) ­­where could it go from here?

38. Example of Rock Cycle: Granite ­­heat and pressure ­­> metamorphic (gneiss) ­­ where could it go from here?

39. Example of Rock Cycle: Plant matter Decomposition and layering  Peat compaction and cementation Lignite  Bituminous coal  heat and pressure ­­> metamorphic Anthracite coal  where could it go from here?

40. 3. Soil Formation a. Results from the continuous weathering (mechanical and chemical) of rocks (into smaller and smaller pieces) combined with living organisms, water, air, and decaying organic material (humus).

41. b.Parent Rock is the bedrock from that when weathered breaks down and begins the process of soil formation. Takes 100’s to 1000’s of years to form 10cm of soil.

42. c. Extremely important to organisms, this is the source of nutrients and water for all living things. (absorbed by plants ›plants eaten by animals › plants and animals die and decay › nutrients returned to soil)

43. Soil Composition (1) 80% are rock particles. There are 3 basic particle sizes.

44. (a)Sand (0.05mm to 2mm size) – good drainage and aeration, doesn’t store water well; unsuitable for plants

49. (b) Silt (0.002mm to 0.05mm size)