Metamorphism and Metamorphic Rocks chap 7

These flashcards cover the key vocabulary and concepts related to metamorphism and metamorphic rocks as outlined in the lecture notes.

Metamorphism

Changes that take place when a rock is subjected to temperatures or pressures very different from where they formed.

Parent Rock

The original rock from which a metamorphic rock is formed; can be metamorphic, igneous, or sedimentary.

Foliation

The preferred orientation of platy and elongate minerals in a metamorphic rock, oriented parallel to the direction of minimum stress.

Directed Pressure

Unequal pressure applied in different directions that results in distortion of a rock body.

Confining Pressure

Uniform stress that applies forces equally in all directions, leading to harder and denser metamorphic rocks.

Index Minerals

Minerals that are stable under specific ranges of pressure-temperature conditions, indicating the metamorphic grade.

Metasomatism

The process by which the composition of a host rock is changed due to the influence of chemically active fluids.

Chemically Active Fluids

Fluids that, at depth, can transport ions and facilitate the recrystallization of minerals during metamorphism.

Metamorphic Grade

The intensity or degree of metamorphism that rocks have experienced, indicated by the sequential appearance of certain minerals.

Three Types of Directed Pressure

Compressional, Tensional, and Shear; each affects rock characteristics differently during metamorphism.