Chapter 4: Rocks

crystallization

formation of mineral crystals as molten rock cools

erosion

transport of weathered sediments by water, wind, ice, or gravity

igneous rock

rock that forms when magma or lava cools

metamorphic rock

rock that forms when existing rock is changed by extreme heat and/or pressure inside Earth

metamorphism

process in which existing rock changes inside Earth to metamorphic rock due to extreme heat and/or pressure

outcrop

exposed rock formation that extends out of the ground

precipitate

solid that separates out of a liquid, usually when the liquid evaporates

rock cycle

continuous series of processes by which rocks change from one type to another

sediment

small particle of soil or rock deposited by wind, water, or other agent of erosion

sedimentary rock

rock that forms when sediments are compacted and cemented or precipitate from liquid

sedimentation

process in which sediments are laid down in a deposit

weathering

chemical or physical breakdown of rocks, soils, or minerals at Earth's surface

Bowen's Reaction Series

order in which minerals undergo melting or crystallization as temperature increases or decreases

extrusive rock

any type of igneous rock that forms on Earth's surface from rapidly cooling lava

felsic rock

type of igneous rock that is made mostly of low-density, light-colored minerals such as quartz and feldspar

fractional crystallization

crystallization of a fraction of the minerals in magma

intermediate rock

type of igneous rock that is intermediate in density and color between felsic rock and mafic rock

intrusive rock

any type of igneous rock that forms beneath Earth's surface from slowly cooling magma

mafic rock

type of igneous rock that is made mostly of high-density, dark-colored minerals such as olivine and pyroxene

partial melting

melting of some but not all of the minerals in rock

pluton

intrusive igneous rock that has cooled in the crust

porphyritic

type of igneous rock texture in which large, visible crystals are found within a matrix of tiny crystals

ultramafic rock

type of igneous rock that contains more than 90 percent mafic minerals such as olivine and pyroxene

vesicular

type of igneous rock texture that includes holes left by gas bubbles in the magma

volcanic rock

another name for extrusive igneous rock because it forms from volcanic activity

biochemical sedimentary rock

rock that forms mostly from the remains of organisms

bioclastic rock

sedimentary rock that forms from sediments that include organic remains

cementation

sticking together of sediments by mineral crystals from fluids

chemical sedimentary rock

rock that forms from the hardening of chemical precipitates

clastic rock

sedimentary rock that forms from inorganic sediments

compaction

squeezing together of sediments by the weight of overlying sediments

lithification

formation of rock from sediments by the processes of compaction and cementation

organic

related to living things

contact metamorphism

changes in rock due to heating by contact with hot magma

foliation

formation of layers in rock due to extreme pressure

regional metamorphism

changes in rock over a large area due to pressure from other rock or geological processes