Rocks Materials of the Solid Earth Flashcards
The rock cycle is a good model for thinking about the transformation of one rock to another due to Earth processes. . Given the right conditions, any kind of rock can be transformed into any other kind of rock.
Rock Cycle
form when hot, molten rock crystallizes and solidifies
Igneous rocks
Completely or partly molten rock that is below Earth’s surface. It consists of a liquid
melt that contains gases (volatiles) such as water vapor, and it may contain solids (mineral crystals).
Magma
Completely or partly molten rock that is on the Earth’s surface
Lava
Molten rock cools and solidifies
Crystallization
When molten rock solidifies at the surface
Extrusive or Volcanic rock
Most magma loses its mobility before reaching Earth’s surface and eventually crystallizes deep below the surface.Igneous rocks that form at depth
Intrusive or Plutonic rock
If the molten material is cooled almost instantly, there is insufficient time for the ions to arrange themselves into a crystalline network. Solids produced in this manner consist of randomly distributed atoms.
Glass
Instant quenching sometimes occurs during violent volcanic eruptions that produce tiny shards of glass
Volcanic ash
Igneous rocks in which is composed almost entirely of light colored silicates such as quartz and potassium feldspar and contain about 10 percent dark silicate minerals
Granitic or Felsic
Rocks that contain at least 45 percent dark silicate minerals and calcium-rich plagioclase feldspar (but no quartz)
Basaltic or mafic
rocks with a composition between granitic and basaltic rocks and contain at least 25 percent dark silicate minerals, mainly amphibole, pyroxene, and biotite mica, with the other dominant mineral being plagioclase feldspar.
Andesitic or intermediate
Igneous rocks that has very low silica content and composed mostly of olivine minerals.
Ultramafic
the overall appearance of a rock, based on the size, shape, and arrangement of its mineral grains
Texture
Igneous rocks that form at Earth’s surface or as small intrusive masses within the upper crust, where cooling is relatively rapid. The crystals that make up fine-grained igneous rocks are so small which can be distinguished only with the aid of a polarizing microscope or other sophisticated techniques
Fine-grained texture
When large masses of magma slowly crystallize at great depth. Consist of a mass of intergrown crystals that are roughly equal in size and large enough so that the individual minerals can be identified without the aid of a microscope
Coarse-grained texture
developed when magma that has been slowly cooling and crystallising within the Earth’s crust is suddenly erupted at the surface, causing the remaining uncrystallised magma to cool rapidly.
Porphyritic texture
The large crystals in porphyritic rocks
Phenocryst
The matrix of smaller crystals wherein larger crystals are embedded.
Groundmass
Igneous rocks that have voids left by gas bubbles that escape as lava solidifies.
Vesicular texture
Nearly spherical openings as lava solidifies
Vesicles
Molten rock that is is quenched and cools quickly to become a solid.
Glassy texture
Formed from the consolidation of individual rock fragments ejected during explosive volcanic eruptions.
Pyroclastic (fragmental) texture
As magma cools, certain minerals crystallize first at relatively high temperatures. At successively lower temperatures, other minerals begin to crystallize.
Vowen’s reaction series
Occurs when the earlier formed minerals are more dense (heavier) than the liquid portion and sink toward the bottom of the magma chamber
Crystal settling
The formation of one or more secondary magmas from a single-parent magma
Magma settling
Created by accumulating existing rocks or fragments of extinct organisms on the Earth’s surface. These are compacted and cemented sediments
Sedimentary rock
indicates the nature of these rocks, for it is derived from the Latin sedimentum, which means “settling,” a reference to a solid material settling out of a fluid.
Sedimentary
Rocks are created from weathered and eroded fragments of pre-existing rock. These eroded pieces are transported, deposited, compacted, and cemented into sedimentary rocks in a process known as lithification.
Detrital sedimentary rock
sediments that originated as solid particles from weathered rocks
Detritus
Coarse (over 2mm) and rounded gravel-sized particles
Conglomerate
Coarse (over 2mm) and angular gravel-sized particles
Breccia
Medium (1/16 to 2mm) and rocks that sand-sized particles prevail
Sandstone
Medium (1/16 to 2mm) If abundant feldspar is present in the rock
Arkose
Fine (1/16 to 1/256mm) and composed mostly of clay-sized sediments intermixed with slightly larger silt-sized grains (0.0625-0.0039)
Siltstone
Very fine (less than 1/256mm) the most common sedimentary rock, is made of very fine-grained sediment and composed mainly of clay minerals
Shale/Mudstone
Form by chemical precipitation that begins when water traveling through rock dissolves some of the minerals. These minerals are carried away from their source and eventually redeposited, or precipitated, when the water evaporates away.
Chemical sedimentary rock
These rocks are formed from precipitation indirectly through life processes of water-dwelling organisms
Biochemical sedimentary rock