1. Chapter 2 Rocks: Mineral Mixtures

2. Section 1 The Rock Cycle

3. rock
always changing
a naturally occurring solid mixture of one or more minerals and/or organic matter

4. rock cycle
the series of processes in which a rock forms, changes from one type to another, is destroyed and forms again by geological processes

5. weathering
the process in which water, wind, ice and heat break down rock
breaks rock down into fragments (which sedimentary rock is made)

6. erosion
the process by which wind, water, ice or gravity transports soil and sediment from one location to another

7. deposition
the process in which sediment is moved by erosion and comes to rest in a new location
sediment is deposited in bodies of water and other low-lying areas
sediment may be pressed and cemented together by minerals dissolved in water to form sedimentary rock

9. uplift
movement within the Earth that causes rocks inside the Earth to be moved to the Earth’s surface
when rock is uplifted to surface weathering, erosion and deposition begin

10. magma
the hot liquid that forms when rock partially or completely melts
3 ways magma can form:
1) when rock is heated
2) pressure is released
3) when rock changes composition 
freezes between 700º and 1250º C

11. composition the chemical makeup of a rock
describes either the minerals or other materials in the rock
limestone = 95% calcite and 5% aragonite 
granite = 55% feldspar, 35% quartz and 10% biotite mica

12. texture
the quality of a rock that is based on the sizes, shapes and positions of the rock’s grains
examples = fine grained, medium grained or coarse grained texture 
can provide clues as to how and where the rock formed

13. SECTION 2 IGNEOUS ROCKS

15. igneous rock forms when hot, liquid rock (magma) cools and solidifies
are located above and below the surface

16. felsic rocks
igneous rocks that are light in color and rich in elements such as aluminum, potassium, silicon and sodium
examples = granite and rhyolite

17. mafic rocks
igneous rocks that are dark in color and rich in calcium, iron and magnesium (poor in silicon)
examples = gabbro and basalt

19. intrusive igneous rock
rock formed from the cooling and solidification of magma beneath the Earth’s surface
usually have a coarse grained texture 
cools very slowly and forms minerals that are large, visible crystals 
common intrusive shapes = plutons, batholiths, stocks, dikes and sills

20. intrusive igneous rock

21. extrusive igneous rock
rock that forms as a result of volcanic activity at or near the Earth’s surface
also called lava rocks
common around volcanoes
cools quickly and contain very small or no crystals

22. extrusive igneous rock

24. lava plateau
when a large amount of lava flows out of fissures onto land and covers a large area
pre-existing landforms are often buried by these lava flows

26. Section 3 SEDIMENTARY ROCK

28. sandstone
when sand grains are compacted or compressed and then cemented together
one of the many types of sedimentary rock

29. sedimentary rock
through erosion rock and mineral fragments are moved from one place to another and eventually deposit in layers. As new layers arrive, old layers are compacted & cemented together binding minerals and rock together
form at or near the Earth’s surface 
forms without heat and pressure 
most noticeable feature is the layers/strata
fossils can only be found in sedimentary rock

31. strata
horizontal layers of rock

32. clastic sedimentary rock
forms when rock or mineral fragments (called clasts) are cemented together by minerals such as calcite or quartz
classified according to the size of fragments: fine, medium and coarse grained

34. chemical sedimentary rock
forms from solutions of dissolved minerals and water
when minerals crystallize out of a solution, such as sea water to become rock
example = halite

35. organic sedimentary rock
forms from the remains or fossils of once living plants and animals
example = many limestone made of skeletons of tiny organisms (coral)
example = coal

36. stratification
the process in which sedimentary rocks are arranged in layers
differ from one another depending on the kind, size and color of their sediment

39. Section 4 Metamorphic Rock

41. metamorphic rock
rocks in which the structure, texture or composition of the rock have changed
all metamorphic rock has 1 of 2 textures: foliated or nonfoliated

42. metamorphism when rocks change shape
all three types of rock can be changed by heat, pressure or a combination of both

43. contact metamorphism when rock is heated by nearby magma
occurs near igneous intrusions

44. regional metamorphism
when pressure builds up in rock that is buried deep below other rock formations or when large pieces of the Earth’s crust collide with each other
causes rock to become deformed and chemically change 
occurs over thousands of cubic kilometers deep within Earth’s crust

45. regional metamorphism

47. foliated
the texture of metamorphic rock in which the mineral grains are arranged in planes or bands
usually contain aligned grains or flat minerals such as mica or chlorite
example= shale slate phyllite schist gneiss

48. foliated

49. nonfoliated
the texture of metamorphic rock in which the minerals are not arranged in planes or bands
commonly made of one or only a few minerals 
Example= quartz sandstone quartzite
or limestone marble

51. deformation
a change in the shape of a rock caused by a force placed on it
folds or bends in rock