| Igneous | Sedimentary | Metamorphic | Structure | Roughrider |
|---|---|---|---|---|
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What is Cumulate?
A rock formed by the accumulation of crystals in a magma through floating or settling.
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What is Weathering?
This Earth process generates sediments from rocks.
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What is a Protolith?
The original unmetamorphosed rock from which a given metamorphic rock is formed.
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What is Boudinage?
An extensional structure termed after the french word for "sausage".
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What is Heterogeneous?
A state of being not uniform in composition or character.
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What is Ultramafic?
A category of rocks derived from the Earth's mantle consisting of less than 45% silica.
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What is Well-Sorted?
Grains have a uniform size as the result of much sediment transport in this sedimentary rock texture.
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What is Retrograde Metamorphism?
Changes in mineral assemblage during uplift and cooling of a rock body refer to this type of metamorphism.
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What is Soft-Sediment Deformation?
Developed in unconsolidated sediments, this class of structures includes load casts, convolute bedding, and flame structures.
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What is Matrix-Supported?
This sedimentary textural term describes a conglomerate in which the clasts are not in contact with one another.
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What is Porphyritic?
A textural term describing a distinct difference in crystal size caused by magma cooling in two stages.
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What is a Turbidite?
This deposit is generated by gravitational flow of sediments into the deep ocean.
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What is Blueschist Facies?
This metamorphic grade is named after a characteristic feature of the minerals glaucophane and lawsonite.
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What is a Shear Zone?
This tabular to sheetlike, planar to curviplanar region is composed of rocks that are more highly strained than adjacent rocks.
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What is Pyrite and Chalcopyrite?
The formulas FeS2 and CuFeS2 represent these two minerals.
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What is Pahoehoe?
A lava flow with a smooth ropy surface created during volcanic eruptions with high effusion rates.
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What is a Polymict Conglomerate?
This type of conglomerate consists of clasts of several different rock types.
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What is a Porphyroblast?
A large, commonly euhedral crystal which has grown within a finer-grained groundmass.
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What are En Echelon Veins?
These veins originate as tension fractures cause by non-coaxial shear and are subsequently filled by mineral precipitation; typically quartz or calcite.
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What is Vuggy?
The characteristic of having small cavities often lined with crystals.
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What is a Chilled Margin?
This glassy to fine-grained zone occurs when magma or lava comes in contact with air, water or a cooler rock body.
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What is the Angle of Repose?
This represents the steepest slope relative to the horizontal plane to which loose sediments can accumulate without slumping.
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What is Granoblastic?
This metamorphic texture describes anhedral, phaneritic, equigranular rocks such as quartzites, marbles, and granulites.
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What is a Strike-Slip or Transform Fault?
This tectonic regime is responsible for Riedel structures, flower structures, and duplexes.
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What is Amphibolite Facies?
Under this metamorphic grade, a metapelite would have the following mineral assemblage: muscovite + biotite + quartz + plagioclase +/- garnet +/in- kyanite/sillimanite.
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What is a Nonconformity?
This type of unconformity separates igneous or metamorphic rocks from overlying sedimentary rocks and usually indicates a long period of erosion prior to the deposition of the sediments.
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