| A | B |
|---|
| andesitic composition | the composition of igneous rocks lying between felsic and mafic |
| basaltic composition | a compositional group of igneous rocks indicating that the rock contains substantial dark silicate minerals and calcium-rich plagioclase feldspar |
| cementation | solidification of sediments by the deposition of dissolved minerals in the tiny spaces between the sedimentary particles |
| chemical sedimentary rock | sedimentary rock consisting of material that was precipitated from water by either inorganic or organic means |
| clastic sedimentary rock | a sedimentary rock made of broken fragments of preexisting rock |
| compaction | process by which sediments are squeezed together by the weight of overlying materials driving out water |
| contact metamorphism | changes in rock caused by the heat from a nearby magma body |
| deposition | the process by which an agent of erosion loses energy and drops the sediment it is carrying; also the process by which water vapor is changed directly to a solid without passing through the liquid state |
| erosion | the incorporation and transportation of material by a mobile agent, such as water, wind, or ice |
| extrusive igneous rock | igneous rock that has formed on Earth’s surface |
| foliated metamorphic rock | a metamorphic rock with a texture that gives the rock a layered appearance |
| granitic composition | a compositional group of igneous rocks that indicate a rock is composed almost entirely of light-colored silicates, mainly quartz and feldspar |
| hydrothermal solution | the hot, watery solution that escapes from a mass of magma during the later stages of crystallization; Such solutions may alter the surrounding rock. |
| igneous rock | a rock formed by the crystallization of molten magma |
| intrusive igneous rocks | igneous rock that formed below Earth’s surface |
| lava | magma that reaches Earth’s surface |
| magma | a body of molten rock found at depth, including any dissolved gases and crystals |
| metamorphic rock | rock formed by the alteration of preexisting rock deep within Earth (but still in the solid state) by heat, pressure, and/or chemically active fluids |
| metamorphism | the changes in mineral composition and texture of a rock subjected to high temperature and pressure within Earth |
| nonfoliated metamorphic rock | metamorphic rock that does not exhibit a banded or layered appearance |
| porphyritic texture | an igneous texture consisting of large crystals embedded in a matrix of much smaller crystals |
| regional metamorphism | metamorphism associated with large-scale mountain-building processes |
| rock | a consolidated mixture of minerals |
| rock cycle | a model that illustrates the origin of the three basic rock types and the interrelatedness of Earth materials and processes |
| sedimentary rock | rock formed from the weathered products of preexisting rocks that have been transported, deposited, compacted, and cemented |
| sediments | loose particles created by the weathering and erosion of rock, by chemical precipitation from solution in water, or from the secretions of organisms and transported by water, wind, or glaciers |
| ultramafic | igneous rock composed mainly of iron and magnesium-rich minerals |
| weathering | the disintegration and decomposition of rock at or near Earth’s surface |
