EARTH MATERIALS LECTURE NOTES


VOCABULARY: crust, Moho, Mohorovicic discontinuity, sima, sial, mantle, core, molten, inner core, outer core, asthenosphere, mineral, rock forming minerals, general properties, special properties, color, streak, luster, hardness, form, cleavage, fracture, tenacity, specific gravity, vitreous, Moh's scale, elastic, odor, magnetism, quartz, feldspar, calcite, diamond, graphite, halite, silicates, carbonates, rock, rock cycle, texture, composition, rock family, igneous, sedimentary, metamorphic, lava, magma, sediment, lithification, metamorphism, cycle, intrusive, extrusive, slow, fast, fast with gas, very fast, mixed, aphanitic, vesicular, vesicles, porphyritic, porphyry, matrix, phenocrysts, pyroclastic, pegmatic, granite, diorite, gabbro, rhyolite, andesite, basalt, pumice, scoria, pegmatite, clastic, chemical, organic, precipitate, evaporite, conglomerate, sandstone, siltstone, shale, limestone, (bituminous) coal, rock symbols, contact metamorphism, regional metamorphism, foliated, non-foliated, gneiss, slate, schist, quartzite, marble, bedrock, outcrop


interior of earth
crust--6 to 40 miles, sial-continental 25 miles +; sima-oceanic 6 miles
Mohorovicic discontinuity--Moho
mantle--most of mass of earth, to depth of 1,800 miles high pressure, iron, magnesium, and rigid
core--2,100 miles radius, iron and nickel
know from earthquake waves

outer 125 miles--both crust and top of mantle is composed of two types of material:
•top--lithosphere--made of sima and sial, rigid
•below--asthenosphere--low strength, low seismic velocity--40-150 miles deep

crust made of minerals
rock forming minerals; quartz SiO2; feldspar; calcite CaCO3; ice H2O; diamond C; graphic C; halite NaCl

general properties--all minerals have
•color, streak, luster, hardness, crystal form, cleavage, fracture, tenacity, specific gravity

special properties--characterics some have
•odor, magnetism

silicates are the largest mineral group
carbonates are also important to rocks

rocks are composed of:

rock cycle--defines rock families and processes

rocks identified by texture and composition
•texture relates to how the rocks formed, each family has its own set of textures; rock only one texture
•composition is minerals or material which composes the rock


IGNEOUS ROCKS

color
environment		lightintermediatedarktexture
rate cool
intrusive (magma)GRANITEdioriteGABBROphaneritic
slow
extrusive (lava)RHYOLITEandesiteBASALTaphanitic
fast
PUMICESCORIAvesicular
fast with gas
OBSIDIAN
glassy
very fast
vesicles--the holes in the vesicular textured rocks

SEDIMENTARY ROCKS


3 divisions: clastic, chemical, and organic clastic size chemical and organic only organic

clastic division is predominantly QUARTZ

chemical and organic is predominantly CALCITE

ROCK SYMBOLS

METAMORPHIC ROCKS

two types of metamorphism
TWO textures

textureROCKbecomes metamorphic
foliatedgraniteGNEISS
shaleSLATE
slate (high grade metamorphism)SCHIST
non-foliatedsandstoneQUARTZITE
limestoneMARBLE
What are the dominant minerals in these rocks?
rocks in the crust
•basalt and gabbro (dark)--42%
•granite and diorite (light to intermediate, intrusive)--22%
•other igneous--1%
•metamorphic--27%
•sedimentary--8% rocks in the outer ten miles
igneous rocks 95% of outer 10 miles

exposed rocks--sedimentary 90% of those exposed


of sedimentary rocks: 75% shale, 12% limestone, 12% sandstone
bedrock--solid rock composing the earth's crust
outcrop--bedrock exposed at the earth's surface


Go to the Volcanism, Folds, and Faults Lecture Notes

Go to the Plate Tectonic Lecture Notes


Go to the Earth Materials Review Questions

Go to the Volcanism, Folds, and Faults Review Questions

Go to the Plate Tectonic Review Questions

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