You are here

Glossary

A (6) | B (6) | C (10) | D (11) | E (7) | F (10) | G (10) | H (1) | I (2) | J (1) | L (7) | M (12) | O (3) | P (11) | Q (3) | R (9) | S (23) | T (5) | U (3) | W (1)
Mafic

An igneous or metamorphic rock composed chiefly of one or more ferromagnesian, dark-colored minerals; also, said of those minerals.

Marble

A metamorphic rock consisting predominantly of fine- to coarse-grained recrystallized calcite and/or dolomite.

Metaigneous Rock

A metamorphosed igneous rock.

Metamorphic Rock

A rock derived from metamorphism of a pre-existing rock.

Metamorphism

Recrystallization of solid rock at variable temperatures and/or pressures below the Earth’s surface, producing changes in the rock’s texture or composition.

Metasedimentary Rock

A metamorphosed sedimentary rock.

Mica

A group of hydrous aluminum-rich silicate minerals, all of which have perfect basal cleavage that allows them to be peeled apart in thin layers (e.g., muscovite, biotite).

Mineral

A naturally occurring, inorganic substance having an orderly internal crystalline structure, characteristic chemical composition, and physical properties.

Modified Slope

A slope that has been significantly altered by humans by construction activities (such as roads, cuts, fills, etc.).

Mud

A mixture of fine silt- and clay-sized particles.

Muscovite

A transparent to silvery-colored potassium-bearing mineral of the mica group.

Mylonite

Any foliated and usually lineated, fine-grained metamorphic rock which shows evidence of strong ductile deformation related to movements along a ductile fault zone.