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42 Cards in this Set
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Igneous Rocks |
When magma solidifies into rocks underneath the earths surface. |
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Extrusive Rocks |
When magma solidifies into rocks above the earths surface |
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Aphanitic Rocks |
These rock cool down fast on or near the earths surface. When this happens the crystals within the rock creates crystals that are not visible to the human eye. "aphanitic igneous rock include basalt, andesite and rhyolite." |
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We base igneous rock classification on two properties, texture and composition. How are these propertiesinfluenced/modified? |
The enviorment where the magma cools and the speed of which the magma cools. |
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What are the following igneous bodies, how do they form, and how are they recognized: |
dikes-A dike or dyke in geological usage is a sheet of rock that formed in a fracture in a pre-existing rock body. , sills- a sill is a intrusion that has intruded between older layers of sedimentary rock, beds of volcaniclava or tuff, or even along the direction of foliation in metamorphic rock. laccoliths- laccolith is a sheet intrusion that has been injected between two layers of sedimentary rock making a mushroom plutons-In geology, a pluton is a body of intrusive igneous rock (called a plutonic rock) that is crystallized from magma slowly cooling below the surface of the Earth. |
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What is a metamorphic rock? |
A metamorphic rock is a result of a transformation of a pre-existingrock. |
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What are the three agents of metamorphism and what is their influence? |
Heat is the most important agent of metamorphism because it provides the energy that drives the chemical reactions responsible for mineral and textural changes during metamorphism. Pressure causes spaces between mineral grains to close and existing to recrystallize into new minerals, and often produces a parallel alignment of mineral to produce a layered or banded appearance. Chemically active fluids in metamorphism serve to facilitate the movement of ions during metamorphic reactions. |
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What are Metamorphic shields? |
The greatest volume of metamorphic rocks are best exposed in the deformed mountain belts and in ancient stable continental interiors known |
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What’s the difference between uniform and differential pressure? Which one generates foliation? |
Metamorphic Rocks |
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What’s the difference between contact and regional metamorphism? How would you recognize them? Which onegenerates foliation? |
Contact metamorphism is a type of metamorphism where rock minerals and texture are changed, mainly by heat, due to contact with magma. The collision of two continental plates or island arcs with continental plates produce the extreme compressional forces required for the metamorphic changes typical of regional metamorphism. |
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Why are index minerals useful when studying metamorphic rocks? |
When an index mineral is found in a metamorphosed rock, it indicates the minimum pressure and temperature the protolith must have achieved in order for that mineral to form. |
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What does it mean to be foliated or nonfoliated? |
the minerals in the original rock to reorient themselves with the long and flat minerals aligning perpendicular to the greatest pressure direction. Nonfoliated metamorphic rocks are formed around igneous intrusions where the temperatures are high but the pressures are relatively low and equal in all directions (confining pressure). |
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Slate, phyllite, schist, gneiss……How do you recognize them? |
T |
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Marble, quartzite, and anthracite are metamorphic versions of which sedimentary rocks? Are these three rocksfoliated? |
Metamorphic Rocks |
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What is a volcano? |
a mountain or hill, typically conical, having a crater or vent through which lava, rock fragments, hot vapor, and gas are being or have been erupted from the earth's crust. |
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How does the amount of Si in a magma relate to its viscosity? |
In general, the viscosity of magma increases as the silica content increases from basalt to rhyolite. |
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What are the characteristics of mafic, intermediate, and felsic magmas/rocks |
Mafic is an adjective describing a silicate mineral or rock that is rich in magnesium and iron, Intermediate rocks are roughly even mixtures of felsic minerals (mainly plagioclase) and mafic mineral Felsic refers to igneous rocks that are relatively rich in elements that form feldspar and quartz. |
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What is a pyroclastic flow? |
A pyroclastic flowis a fast-moving current of hot gas and rock. |
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What is/are AA vs pahoehoe, pillow lava? |
ahoehoe has a smooth, billowy, ropy surface and has at times been likened to the surface texture of a pan of chocolate brownies. `a`a has a rough, jagged and clinkery surface. Pillow lavas are lavas that contain characteristic pillow-shaped structures that are attributed to the extrusion of the lava under water |
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What makes composite (strato-volcanoes) so dangerous? Hint: It’s related to viscosity |
The viscosity i |
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What are the differences between the following, and how do they form?- Stratovolcano (composite volcano), shield volcano |
Stratovolcanoes are common at subduction zones, forming chains along plate tectonic boundaries where oceanic crust is drawn under continental crust This is caused by the highly fluid lava they erupt, which travels farther than lava erupted from stratovolcanoes. This results in the steady accumulation of broad sheets of lava, building up the shield volcano's distinctive form. |
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What are the two main types of plate margins and what kinds of geologic features and activity are found alongthem? - Does each plate boundary have the same type of activity/features? - Consider Death Valley NP, the Appalachian Trail, and Mt. St. Helens - horsts and grabens vs. folding/warping of strata |
Terms and themes for volcanism (Hawaii Volcanoes and Mt. St. Helens, Yellowstone NP): |
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What is the rock cycle and how does it work? |
Terms and themes for volcanism (Hawaii Volcanoes and Mt. St. Helens, Yellowstone NP): |
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Eruption prediction: what are the signs of an impending eruption? |
Terms and themes for volcanism (Hawaii Volcanoes and Mt. St. Helens, Yellowstone NP): |
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What’s the difference between weathering and erosion? |
Weathering and Erosion (Bryce Canyon NP, Badlands NP) Chapter 9 |
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What is physical weathering?- How do the following physical weathering processes work?o Frost actiono Pressure releaseo Organisms |
Weathering and Erosion (Bryce Canyon NP, Badlands NP) Chapter 9 |
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How does talus form? |
Weathering and Erosion (Bryce Canyon NP, Badlands NP) Chapter 9 |
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What is chemical weathering?- How do the following types of chemical weathering work?o Solution, oxidation |
Weathering and Erosion (Bryce Canyon NP, Badlands NP) Chapter 9 |
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What’s the relationship between weathering and: particle size, parent material |
Weathering and Erosion (Bryce Canyon NP, Badlands NP) Chapter 9 |
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What are the differences between the following types of weathering features: weathering rind, spheroidalweathering, differential weathering, exfoliation |
Weathering and Erosion (Bryce Canyon NP, Badlands NP) Chapter 9 |
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What are sorting, roundness, and abrasion? How do they relate to distance of transport? |
Depositional Environments (Grand Canyon NP) Chapters 10, 11 |
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What is a depositional environment? What are some examples of marine, nonmarine, and transitional depositionalenvironments? |
Depositional Environments (Grand Canyon NP) Chapters 10, 11 |
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How does uniformitarianism apply to the study of sediments, sedimentary rocks, and paleo environmental interpretation? |
Depositional Environments (Grand Canyon NP) Chapters 10, 11 |
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What is lithification and what are the two main processes that occur during lithification? |
the process or processes by which unconsolidated materials areconverted into coherent solid rock, as by compaction or cementation Compaction and Cementation |
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What are clastic vs. nonclastic rocks? How do they form? |
Clastic sedimentary rocks form by weathering processes which break down rocks into pebble, sand, or clay particles by exposure to wind, ice, and water. Nonclastic sedimentary rocks form from chemical reactions |
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How would you recognize sandstone, siltstone, and claystone? |
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What are some examples of nonclastic rocks? |
Limestone Rock salt Rock gypsum Chert |
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Why/how is coal different from other “nonclastic” rocks? Why can we apply the term “bioclastic” to coal? |
Coal is different because coal is comprised with several plants and fossils |
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How do evaporites form? |
Evaporites are sediments chemically precipitated due to evaporation of an aqueous solution |
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What are sedimentary structures? |
Sedimentary Structures show the many fine-scale structures that give an indication of howthe sediment formed and in which environment. |
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The following are types of sedimentary structures. How would you recognize them, and how do they form?Asymmetric vs. symmetric ripples, crossbedding, mudcracks, graded bedding. |
Mud Cracks show indicate very shallow waterdepths. Cross beds often indicatedunes, Normally graded beds generally represent depositional environments which decrease in transport energy as time passes, but also form during rapid depositional events. |
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What’s the difference between a body fossil and trace fossil? |
bones, claws, teeth, skin, embryos footprints, nests, dung, toothmarks |
