Igneous Rocks1
The general name given to all igneous rocks formed on the Earth's surface.
What is an extrusive or volcanic igneous rock?
A chart illustrating the order of crystallization as magma/lava cools.
What is the Bowen Reaction Series?
The four factors that control the generation of magma from solid rock.
What are temperature, pressure, volatiles, and composition?
The three basic classifications of sedimentary rocks.
What are clastic, chemical, and biochemical sedimentary rocks?
These rocks form from pre-existing rocks when they are subjected to substantial heat and pressure.
What are metamorphic rocks?
The general name given to all igneous rocks formed deep within the Earth's crust. These rocks contain crystals that are easily visible with the unaided eye.
What is an intrusive or plutonic igneous rock?
The processes by which the same magma chamber can generate igneous rocks of different compositions.
What is magmatic differentiation?
The Earth's natural increase in temperature with depth. The average change in the upper crust is about 25°C/km.
What is the geothermal gradient?
These sedimentary rocks consist of grains or pieces of pre-existing rocks and are categorized primarily by grain size.
What are clastic sedimentary rocks?
The alignment of minerals perpendicular to compressional forces.
What is foliation?
The cycle by which the Earth uses pre-existing rocks to create new rocks.
The process by which minerals with high magnesium and/or iron and low silica content crystallize first as magma cools, effectively enriching the remaining liquid with silica.
What is fractionation?
As temperature increases within the Earth's crust for whatever reason, minerals with higher silica content will melt sooner than those with lower silica content.
What is partial melting?
These sedimentary rocks are formed by precipitation from a solution, for example, crystalline limestone, micrite, travertine, cryptocrystalline quartz (agate, flint)
What are chemical sedimentary rocks?
This property is caused by the parallel orientation of platy (clay) minerals which permits this particular metamorphic rock to be quarried in thin (or thick) plates.
What is slaty (or rock) cleavage?
These igneous rocks are composed of minerals that are rich in iron and/or magnesium and have low silica content.
What are mafic (or basaltic) igneous rocks?
The process of changing the overall composition of magma as chunks of country rock fall into the magma chamber and melt.
What is assimilation?
The melting of solid rock in the Earth's mantle due to a change in pressure even though the temperature does not change.
What is decompression melting?
These sedimentary rocks contain fossils (whole or fragments), for example, fossiliferous limestone, chalk, diatomite).
What are biochemical sedimentary rocks?
The process of forming metamorphic rocks that results in a bulk (or overall) chemical composition that is more or less unchanged from that of the protolith.
What is the isochemical process?
Igneous rocks in this category have a high silica dioxide (silica) content and contain light-colored minerals.
What are felsic (or granitic) igneous rocks?
Unmelted pieces of country rock that fall into the magma chamber but do not melt. In the solid rock, they appear as chunks of a different composition (mafic) than the main portion of the igneous rock, which is felsic.
What are xenoliths?
Water along subducting plates allows rocks to melt sooner than if water was not present. When water is present in the system, rocks melt at a shallower depth (lower temperature).
What is flux melting or wet melting?
Principal characteristics possessed by all sedimentary rocks.
What are strata (or beds) and bedding planes?
A type of metamorphism resulting from high differential stress and high temperatures during mountain building. This process produces the greatest volume of metamorphic rocks.
What is regional metamorphism?