Introduction and Review For Igneous and Metamorphic Petrology

Petrology

The study of rocks, including their physical, chemical, spatial, and chronological properties as well as the geological processes responsible for their formation.

Igneous rock

Rocks formed through the cooling and solidification of magma or lava.

Metamorphic rock

Rocks that have undergone transformation due to heat and pressure, changing the texture and mineralogy of the original rock.

Lithosphere

The rigid outer layer of the Earth, consisting of the crust and upper mantle.

Asthenosphere

The semi-solid layer of the mantle located beneath the lithosphere, where convection occurs.

Tectosilicates

Framework silicates that include minerals like feldspar and quartz.

Inosilicates

Silicates that form chain-like structures; includes minerals such as pyroxenes and amphiboles.

Nesosilicates

Silicates that form isolated tetrahedra, including minerals like olivine and garnet.

Geothermal gradient

The rate at which the temperature increases with depth in the Earth's interior.

Divergent boundary

A tectonic plate boundary where two plates move away from each other, commonly associated with mid-ocean ridges.

Convergent boundary

A tectonic plate boundary where two plates move toward each other, leading to subduction or continental collision.

Transform boundary

A tectonic plate boundary where two plates slide past each other horizontally, causing strike-slip faults.

Hydrothermal metamorphism

Metamorphism that occurs when ocean water circulates through rocks, altering their mineral composition.

Subduction

The process by which one tectonic plate moves under another and is forced into the mantle.

Mantle

The thick layer of the Earth located beneath the crust and above the core, composed of silicate rocks.

Crystalline structure

The ordered arrangement of atoms or molecules found in crystalline solids, significant in mineral identification.

Pressure gradient

The increase in pressure with depth in the Earth, typically measured in GPa/km.

Plate tectonics

The scientific theory that describes the movement of the Earth's plates and the forces involved in that movement.

Mineralogy

The study of minerals, including their crystallography, structure, chemistry, and properties.

Almandine

A specific type of garnet, characterized by the formula Fe3Al2Si3O12.

Olivine

A common nesosilicate mineral with the chemical formula (Mg,Fe)2SiO4, often found in igneous rocks.

Fractional crystallization

A process in magma generation where different minerals crystallize at different temperatures, leading to a change in composition.