Chapter 8 Flashcards
Low-grade metamorphism that occurs in the lowest layers of very thick accumulations of sedimentary strata
Burial metamorphism
Stress that is applied uniformly in all directions
Confining pressure
Changes in rock caused by the heat from a nearby magma body
Contact metamorphism
Forces that are unequal in different directions
Differential stress
A term for a linear arrangement of texture features often exhibited by metamorphic rocks
Foliation
A texture of metamorphic rocks in which dark and light silicate minerals are separated; giving the rock a banded appearance
Gneissic texture
Chemical alterations that occur as hot, ion-rich water circulated through fractures in rock
Hydrothermal metamorphism
A zone or halo of contact metamorphism found in the rock surrounding an igneous intrusion
Aureole
Metamorphism that occurs when meteorites strike earths surface
Impact metamorphism
A mineral that is a good indicator of the metamorphic environment in which it formed. Used to distinguish different zones of regional metamorphism
Index mineral
The changes in mineral composition and texture of rock subjected to high temperatures and pressures within earth
Metamorphism
When substantial chemic change accompanies metamorphism
Metasomatism
A rock exhibiting both igneous and metamorphic rock characteristics. Such rocks may form when light colored silicate minerals melt and then crystallize, while dark minerals remain solid
Migmatite
Metamorphic rocks that do not exhibit foliation
Nonfoliated texture
The rock from which a metamorphic rock formed
Parent rock
Metamorphism associated with large scale mountain building
Regional metamorphism
The tendency of rocks to split along parallel, closely spaced surfaces. These surfaces are often highly inclined to the bedding planes in the rock
Rock cleavage
A type of foliation characteristic of coarser grained metamorphic rocks. Such rocks have parallel arrangements of Plath minerals such as the Micas.
Schistosity
The type of foliation characteristic of slates in which there is a parallel of fine-grained metamorphic minerals
Slaty-cleavage
Results from the crushing and shearing of rock during tectonic movement, generally localized along fault planes
Cataclastic metamorphism
A group of associated minerals that are used to establish the pressures and temperatures at which rocks undergo metamorphism
Metamorphic facies
