Rock Identification and Classification

These flashcards cover key concepts and definitions regarding rock identification and classification based on the lecture notes.

Igneous Rock Identification

Identification based on the cooling and solidification of magma/lava, including texture and composition.

Aphanitic Texture

Fine-grained texture indicating rapid cooling at or near the surface; characteristic of extrusive rocks.

Phaneritic Texture

Coarse-grained texture indicating slow cooling underground; characteristic of intrusive rocks.

Felsic Composition

Light color, low density, rich in quartz and feldspar; examples include granite and rhyolite.

Mafic Composition

Dark, dense, rich in pyroxene and olivine; examples include gabbro and basalt.

Detrital Sedimentary Rocks

Rocks formed from the accumulation of fragments of other rocks; includes shale, sandstone, breccia, and conglomerate.

Fossiliferous Limestone

A type of limestone that contains fossils or fossil fragments.

Metamorphic Rock Formation

Formation through heat and pressure leading to recrystallization; can result in foliated or non-foliated textures.

Foliated Metamorphic Rocks

Metamorphic rocks with a layered or banded appearance, such as slate, schist, and gneiss.

Regional Metamorphism

Metamorphism associated with mountain building and tectonic forces.

Foliation

A planar arrangement of mineral grains or structural features within a rock, often resulting from directional pressure (e.g., schist, gneiss).

Parent Rock (Protolith)

The original rock from which a metamorphic rock forms (e.g., limestone becomes marble).

Metasomatism

 The process by which the chemical composition of a rock changes due to the interaction with fluids.

Index Minerals

Minerals that are stable only within specific temperature and pressure conditions, used to indicate the metamorphic conditions (e.g., garnet, kyanite)

Anatexis

The partial melting of rocks during metamorphism, leading to the formation of magma.

Catazonal Metamorphism

Metamorphism that occurs at significant depths in the crust with high pressure and temperature.

Hydrothermal Metamorphism

Metamorphism that occurs due to the interaction of hot, chemically active fluids with rocks.

Cleavage Plane

 A plane of weakness along which a mineral can easily break.

Saturation

The state of a solution when no more solute can dissolve at a given temperature and pressure.

Geological Time Scale

 A chronological dating system used to describe the timing and relationships of events in Earth's history.

Alluvium

Sediment deposited by rivers, typically consisting of sand, silt, and clay.

Conglomerate

A clastic sedimentary rock composed of rounded gravel-sized particles.

Breccia

A clastic sedimentary rock composed of angular gravel-sized particles

Siltstone

A fine-grained clastic sedimentary rock composed primarily of silt-sized particles.

Schistosity

A type of foliation in schist that allows the rock to split easily into thin layers.

Cataclasite

A fine-grained, non-foliated metamorphic rock formed from the mechanical disaggregation of rock due to faulting.

Ore

profitable mineral source

Ganue

waste material

Smelting

extract metal

Beneficiation

concentrate ore

Reclamation

restore mined land

Cleave

The ability of a mineral to break along preferred planes of weakess