Chapter 2 Vocab Flashcards
Rock formed by the crystallization of molten magma
Igneous rock
A model that illustrates the origin of the three basic rock types and the interrelatedness of earth materials and processes
Rock cycle
A body of molten rock found at depth, including any dissolved gases and crystals
Magma
Magma that reaches earth’s surface
Lava
Igneous activity that occurs outside the crust
Extrusive/volcanic
Igneous rock formed below earths surface
Intrusive/platonic
The size,shape, and distribution of the particles that collectively constitute a rock
Texture
Texture of igneous rocks in which the crystals are too small for individual minerals to be distinguished with the unaided eye
Fine-grained texture
Fine-grained igneous rocks that contain many small cavities called vesicles, which are openings on the outer portion of a lava flow that were created by escaping gases
Vesicular texture
Igneous rock texture in which the crystals are roughly equal in size and large enough that individual minerals can be identified with the unaided eye
Coarse-grained texture
Igneous texture consisting of large crystals embedded in a matrix of much smaller crystals
Porphyritic texture
Term used to describe the texture of certain igneous rocks, such as obsidian, that contain no crystals
Glassy texture
Compositional group of igneous rocks in which the rock is made up almost entirely of light-colored silicates
Granitic/felsic composition
Compositional group of igneous rocks in which the rock contains substantial dark silicate minerals and calcium-rich plagioclase feldspar
Basaltic/mafic composition
Compositional group of igneous rocks in which the rock contains at least 25% dark silicate minerals
Intermediate/andesitic composition
Compositional group of igneous rocks in which the rock contains mostly olivine and pyroxene
Ultramafic composition
Illustrates the relationship between magma and the minerals crystallizing from it during the formation of igneous rocks
Bowens reaction series
The downward movement of minerals during the crystallization of magma
Crystal settling
Mechanical breakup of rock caused by the expansion of freezing water in cracks and crevices
Frost wedging
A large dome shaped structure usually composed of granite, formed by sheeting
Exfoliation dome
Rock formed from the weathered products of preexisting rocks that have have been transported, deposited, and lithified
Sedimentary rock
Unconsolidated particles created by the weathering and erosion of rock, by chemical precipitation from solution in water, or from secretions or organisms and transported by water, wind, or glaciers
Sediment
Rock formed from the accumulation of material that originated and was transported in the form of solid particles derived from both mechanical and chemical weathering
Detrital sedimentary rock
Sedimentary rock consisting of material that was precipitated from water by either inorganic or organic means
Chemical sedimentary rock
A sedimentary rock composed of material that was extracted from water by organisms to create hard parts such as shells
Biochemical sedimentary rock
A sedimentary rock formed of material deposited from solution by evaporation of the water
Evaporite
Carbon-rich substances derived from living things that are in various stages of decomposition
Organic matter
The process of converting sediments to solid rock
Lithification
Sediment that is carried by a stream along the bottom of its channel
Bed loads
The remains or traces of organisms preserved from the geologic past
Fossils
Rock formed by the alteration of preexisting rock deep within earth by heat, pressure, and/or chemically active fluids
Metamorphic rock
The changed in mineral composition and texture of a rock subjected to high temperatures and pressures within earth
Metamorphism
Changes in rock caused by the heat from a nearby magma body
Contact metamorphism
Metamorphism associated with large-scale mountain-building processes
Regional metamorphism
A linear arrangement of textural features that metamorphic rocks often exhibit
Foliation
