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Rocks!
Mr. Drake Phy. Sci.
58
Geology
10th Grade
03/14/2007

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Cards

Term
Name the three kinds of rocks.
Definition
Igneous, sedimentary, metamorphic.
Term
What are igneous rocks?
Definition
Rocks formed by the cooling and hardening of hot molten rock from inside the Earth.
Term
What are sedimentary rocks?
Definition
Rocks formed by the hardening and cementing of layers of sediment.
Term
What are metamorphic rocks?
Definition
Rocks formed when rocks that already exist are changed by heat and pressure into new rocks.
Term
What is a rock?
Definition
A group of minerals bound together in some way.
Term
Distinguish between intrusive and extrusive.
Definition
Intrusive igneous rocks have formed from slowly cooling underground, making them coarse-grained with more crystals. Extrusive igneous rocks have formed from quickly cooling once reaching the Earth's surface. This fast cooling makes them fine-grained with less crystals.
Term
What is another term for intrusive? For extrusive?
Definition
Plutonic. Volcanic.
Term
What are the two general kinds of magma?
Definition
Felsic and Mafic.
Term
What are felsic rocks?
Definition
Light-colored, high silica igneous rocks. Most intusive rocks are felsic.
Term
What are mafic rocks?
Definition
Dark-colored, low-silica igneous rocks. Most extrusive rocks are mafic.
Term
What is the texture of a rock?
Definition
How it feels (bumpy, smooth, etc.). Depends on the size, shape, and arrangement of its minerals' crystals.
Term
What is the most important factor affecting texture?
Definition
Crystal size.
Term
What does the crystal size in an igneous rock depend upon?
Definition
How fast the magma hardens and the amount of gas dissolved into the magma. The more dissolved gas, the bigger the crystals grow.
Term
What is the name for a coarse-grained texture?
Definition
Granular. ex. granite
Term
List the textures for igneous rocks.
Definition
Coarse-grained(granular), fine-grained, glassy, vesicular(???????).
Term
What is a porphyry?
Definition
A rock with 2 distinctly different textures. Large crystals surrounded by a fine-grained mass of rock.
Term
Name three families of igneous rocks.
Definition
The granite family, the gabbro family, and the diorite family.
Term
What are the three main kinds of sedimentary rock?
Definition
Clastic, chemical, organic.
Term
What are clastic rocks? Give an example.
Definition
Sedimentary rocks fromed from fragments of other rocks.Ex. shale, sandstone, conglomerate.
Term
What are chemical rocks? Give an example.
Definition
Sedimentary rocks formed from mineral grains that fall out of a solution(precipitate) by evaporation or by chemical action. Ex. Rock salt
Term
What are organic rocks? Give an example.
Definition
Sedimentary rocks formed from the remains of plants and animals. Ex. coal.
Term
How do clastic rocks form?
Definition
Small rock fragments rae picked up and smoothed out by water, the wind and other elements. The coarse sediments are eventually deposited and cemented together by a natural agent. continue later
Term
What are some natural cements used in clastic rocks?
Definition
Silica, calcite, and iron oxides
Term
What is conglomerate?
Definition
The coarsest clastic rock. Cemented mixture of rounded pebbles and sand grains. Pebbles may be any rock material.
Term
What is sandstone?
Definition
Clastic rock. Made of grains of quartz, up to 30% air(very porous), Rough, gritty, durable.
Term
What is shale?
Definition
Clastic rock made from clays and sediments. Impermable, smooth, soft, easily broken.
Term
Describe the granite family. Give examples.
Definition
Forms from felsic magmas. All rocks have orthoclase feldspar and quartz. Ex. Granite, rhyolite, obsidian, pumice.
Term
Describe the Gabbro family. Give examples.
Definition
Igneous rocks forming from mafic magmas. Made mainly from dark plagioclase feldspar and augite. Generally dark in color and denser thean granite family. Ex. Gabbro, basalt, basalt glass.
Term
Describe the diorite family. Give examples.
Definition
Igneous rocks that have a compostion and color between that of the granite and gabbro families. Ex. Diorite, andesite.
Term
What is the most common continetal igneous rock?
Definition
Granite.
Term
What is stratification?
Definition
Arrangement in visible layers. Seen in sedimentary rocks.
Term
What are fossils?
Definition
The remains, impressions, or any other evidence of plants or animals preserved in a rock.
Term
What are ripple marks?
Definition
Formed by the action of winds, streams, waves, or currents on sand. Found on some sandstones.
Term
What are mud cracks?
Definition
Cracks that develop when deposits of wet clay dry and contract.
Term
What are geodes?
Definition
Rocks that have a hollow area that is lined with crystals of quartz or calcite.
Term
What three things cause rocks to metamorphize?
Definition
Heat, pressure, and chemicals.
Term
How are most of the metamorphic rocks formed?
Definition
By regional metamorphism.
Term
What is regional metamorphism?
Definition
Metamorphism that occurs when large areas of rock undergo intense heat and pressure causing them to metamorphize. Affects a very large area.
Term
During metamorphism what happens?
Definition
Pressure moves the grains closer together making the rocks denser and less porous. Heat and chemicals may rearrange the particles. Minerals may be reformed, or ne minerals may be formed.
Term
Sedimentary --> Metamorphic
Conglomerate(or granite)--> 1.
Sandstone--> 2.
Limestone--> 3.
Shale--> 4.
Definition
1. Gneiss
2. Quartzite
3. Marble
4. Slate then schist
Term
What are the two metamorphic textures?
Definition
Foliated and nonfoliated.
Term
What is foliation?
Definition
A feature in metamorphic rocks that allows the rocks to easily split into layers.
Term
What rock has the coarsest foliation?
Definition
Gneiss
Term
What is unique about gneiss?
Definition
Its minerals are arranged in cardboard thick parallel bands. Bands of light colored minerals(quartz and feldspar) alternate with dark bands(hornblende and biotite).
Term
What is contact metamorphism? Give an example.
Definition
A process that occrus when hot magma forces its way onto overlying rock. The heat of the magma bakes the rocks. Much less rock is affected. Foliation is NOT produced. Ex. Hornfels
Term
Name 6-8 rock forming minerals.
Definition
Quartz, feldspar, mica, calcite, hematite, hornblende.
Term
Igneous Rocks:
A. Formation?
B. Hard or soft?
C. Primary or secondary?
D. Origin?
E. Main minerals?
F. Main colors?
G. Main textures?
Definition
A. Magma or lava
B. Hard
C. Primary
D. Top, mid, low
E. Quartz, feldspars, micas(biotite, muscovite)
F. Blacks, pinks, reds, whites
G. Coarse-grained, fine-grained, glassy, vesicular
Term
Sedimentary rocks:
A. Formation?
B. Hard or soft?
C. Primary or secondary?
D. Origin?
E. Main minerals?
F. Main colors?
G. Main textures?
Definition
A. Lithification (pressure and cement)
B. Soft
C. Secondary
D. Top, mid
E. Calcite, quartz, feldspar,hematite,mica
F. Earth tones
G. clastic, chemical , organic
Term
Metamorphic Rocks:
A. Formation?
B. Hard or soft?
C. Primary or secondary?
D. Origin?
E. Main minerals?
F. Main colors?
G. Main textures?
Definition
A. Pressure(buried), heat(encounters magma or lava), or chemcials(acids) on a preexisting rock
B. Hardest
C. Secondary
D. Top, mid
E. Everything
F. Everything
G. Foliated or nonfoliated
Term
After metamorphism , a rock is....
Definition
harder, denser, and shinier.
Term
Mineral>Rock>Meta-rock
1. Quartz>Sandstone>?
2. Feldspar>Shale>?>?
3. Quartz,Feldspar,Hornblende>Igneous rock>?
4. Calcite>Limestone>?
Definition
1. Quartzite
2. slate, schist
3. gneiss
4. marble
Term
List the three classes of rock in order of their abundance in Earth's crust.
Definition
Ig, Sed, Met
Term
What is a conchoidal fracture? Give examples.
Definition
A shell-shaped fratcure with sharp edges. Ex. Chert and obsidian
Term
What are ferromagnesian minerals?
Definition
Iron magnesium silicates of a dark color. ????????????? What else?????????
Term
What is porosity?
Definition
The amount of a rock that is air.
Term
What is permeability?
Definition
The ability for water the pass through rock.
Term
What are nodules? Give an example.
Definition
A mineral mass that has a different composition or is more weathering resistant than its surrounding rock. These are normally rounded in shape. Example: chert masses in a limestone rock unit.
Term
What are concretions?
Definition
A volume of sedimentary rock in which a mineral cement fills the porosity (i.e. the spaces between the sediment grains). Concretions are often ovoid or spherical in shape, although irregular shapes also occur.
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