METAMORPHIC ROCKS PG. 45

METAMORPHIC ROCKS Undergo Metamorphism Means to change form Often look much different than the parent rock Have folds in them due to extreme forces

FORMATION Occur at elevated temperatures and pressures Can also occur from hydrothermal solutions Water based solutions that heat up and carry ions and change the chemical composition of the rock Extend into the upper mantle Can form in two different ways

CONTACT METAMORPHISM Hot magma moves into rock Changes in rocks are minor Common example: Marble (magma intrudes limestone)

REGIONAL METAMORPHISM occurs during mountain building Large areas of rock are subjected to extreme temps and pressure Results in large scale deformation

CLASSIFICATION OF METAMORPHIC ROCKS Can be classified by texture and composition 2 types: Foliated: Happens during contact metamorphism Rocks become more compact and more dense Has a layered or banded appearance due to the alignment of minerals Ex. Gneiss Non-foliated Does not have a banded appearance Most contain only one mineral Ex. Marble

CLASSIFICATION OF MAJOR METAMORPHIC ROCK