BIOTITE		dark colored mica
SUBDUCTION		foliated, looks like banded granite
BASALT		when one plate is converges and dives under the other
COMPOSITE		type of igneous rock that cools fast above ground , notallowing larger crystals to form
GABBRO		clear mineral; fizzes when HCl applied; you see double
SHALE		tall gently sloped volcanoe; lava very fluid; non-explosive
CONVECTION		mechanism responsible for plate movement and earth magnetic field
CONGLOMERATE		fastest type of earthquake wave; travels through all materials
EXTRUSIVE		lead sulfide mineral; blocky cleavage; metallic luster
LONGITUDINAL		sedimentary, clastic, has pebbles
CALCITE		olive green mineral containing a lot of iron and magnesium
SLATE		only half as fast as P waves; can't go through liquids or gases
TRANSFORM		igneous rock; extrusive; cooled so quickly that there are no grains
SILICATE		dark gray , igneous rock, fine grained; makes up most of oceanic crust
FELDSPAR		location of the surface directly above the earthquake source
GALENA		igneous rock; salt and peppery; light colored; intrusive
CINDER CONE		steep, tall, explosive type of volcano made of different layers of ash, lava, cinders, mud
RIDGE		deep depression in subduction zone
GRANITE		when shale undergoes metamorphism it converts to this
RHYOLITE		most common general category of mineral in crust; made of silicon and oxygen atoms with tetrahedral units
SHIELD		clastic sedimentary; clay
EPICENTER		formed at the spreading center
GNEISS		"field mineral"; most common specific mineral in continental crust
SHEAR		igneous rock; extrusive; fine grained; light-colored
TRENCH		igneous rock; greenish black; dark colored; intrusive
OLIVINE		lavea explodes into the air, rains down small cooled fragements that pile up
OBSIDIAN		parallel sliding plate boundary