Geology 101 Test 2: WVU Renton – Flashcards

rock that crystallizes directly from molten rock

The temperature at which a solid melts or a liquid solidifies under a specific pressure, generally atmospheric pressure at sea level.

Melting that is triggered by a drop in surrounding pressure

The incomplete melting of a rock based on the varying melting temperature of its components

A description of the order in which various minerals crystallize based on melting/freezing points.

The general physical appearance of a rock as observed in reflected light

Type of igneous rock that solidifies on the earth's surface; also called volcanic

Rock that solidifies on the surface of the earth and is produced by or pertains to volcanoes; also called extrusive

The fine-grained rock texture that results from crystals too small to be seen with the naked eye

Type of igneous rock that solidifies inside the earth; also called plutonic

Rock that solidifies inside the earth; also called intrusive

The course-grained rock texture that results from larger crystals

Rocks are composed of minerals, each of which has its own melting/freezing point. Thus, the rock will melt over a range of temperatures rather than a single temperature.

If a rock is under pressure, its melting point is increased and so it remains a solid at a higher temperature than it would at sea level pressure. If the pressure drops, the melting point decreases, and the already hot rock may start to melt.

The presence of water lowers the melting point of rock.

Because rocks are made of minerals that melt at different temperatures, a rock will melt only partially if the temperature is between the melting point of two of its minerals. The mineral that melts at the lover temperature will melt whereas the mineral with the higher melting temperature will stay solid.

In general, mafic minerals tend to melt at higher temperatures than felsic minerals. There is plenty of overlap, however.

These textures are caused by the rate of cooling. Slow cooling allows crystals to form larger, which produces a phaneritic texture. Fast cooling causes tiny crystals and a fine, aphanitic texture.

Phenocrysts are the large crystals in a porphyritic rock whereas groundmass is the aphanitic rock that surrounds the phenocrysts.

Granite and rhyolite are both felsic rocks but have different textures. Granite is phaneritic and rhyolite is aphanitic. Likewise, gabbro and basalt are mineral equivalents with different textures: gabbro is phaneritic and basalt is aphanitic.

Magmas contain different combinations of minerals and melt under different conditions. Partial melting causes the composition of magma to vary, depending upon the conditions under which the rock is melting

Divergent boundaries produce hot, fluid basaltic magma.

Convergent boundaries tend to produce cooler, more viscous felsic magmas.

Basaltic magmas contain mafic minerals that are less viscous when melted; that is, they have less resistance to flow. Thus, they can make the journey to Earth's surface relatively rapidly, before they cool enough to crystallize. Felsic magmas contain silica, which is more viscous when melted; thus these rocks have a higher resistance to flow. The increased viscosity impedes their journey to Earth's surface, and they often cool enough to crystallize before they get there.

Plutons are bodies of rock that have solidified underground.

Tabular plutons are flat whereas massive plutons have an irregular shape.

Both are tabular plutonic bodies, but a dike is discordant and cuts across rock layers whereas a stock has less than 100 square kilometers exposed.

Igneous rock texture that contains crystals exceeding one centimeter in diameter

Type of rock composed of large crystals, called phenocrysts, that are cemented together by fine-grained rock, called groundmass

The large crystals cemented together by groundmass to form porphyritic rock.

The aphanitic rock around phenocrysts in a porphyritic rock

Type of texture that includes small air cavities called vesicles.

A vesicular rock, also known as scoria.

A vesicular rock, also known as cinder

An ultralight, felsic vesicular rock

Refers to materials, such as rock, glass, ash, and scoria, that are ejected during violent volcanic eruptions.

A felsic rock that has a glassy texture as a result of very quick cooling.

Igneous rocks composed almost entirely of mafic minerals with very few felsic minerals

An ultramafic rock thought to compose a large proportion of the mantle

Igneous rocks containing a balance of mafic and felsic minerals

One example of a phaneritic rock with felsic composition; the course-grained equivalent to rhyolite

One example of an aphanitic rock with mafic composition, the fine-grained equivalent to granite

One example of an aphanitic rock with mafic composition, the fine-grained equivalent of gabbro

One example of a phaneritic rock with mafic composition; the coarse-grained equivalent of basalt.

One example of a phaneritic rock with inermediate composition; the coarse-grained equivalent of andesite.

One example of an aphanitic rock with intermediate composition; the fine grained equivalent of diorite

A rare aphanitic ultramafic rock; the fine-grained equivalent of perodotite.

Resistance to flow

A rock body formed by the crystallization of magma below the earth's surface; an igneous intrusion, also called a pluton

An irregularly shaped plutonic body

A flat plutonic body

The rock into which an igneous intrusion is injected

Lying parallel to existing rock layers

Cutting across existing rock layers

A flat igneous intrusion that extends parallel to existing rock layers; a tabular, concordant feature

A flat igneous intrusion that cuts across existing rock layers; a tabular, discordant feature

A massive plutonic feature whose exposed surface exceeds 100 square kilometers (40 square miles)

A massive plutonic feature whose exposed surface is less than 100 square kilometers (40 square miles)

a processing by which magma intrudes into country rock, breaking off fragments of the country rock that then sink into the magma

A fragment of country rock that has been broken off and fallen into magma, which solidified around it.

A tabular plutonic feature that inflates to a lens shape, flat on the bottom and curved on the top

A cylindrical plutonic body formed when lava solidifies within a volcano's vent

An elongated plutonic body

A physical weathering process by which exposed rocks break down into smaller particles or into their chemicals components

A physical weathering process in which rocks break down into smaller and smaller particles

A mechanical weathering process in which particles colliding with rocks breaks loose other particles

The process in which wind, water, or glaciers removes weather particles from the environment

The mechanical weathering process in which water repeatedly enters cracks and joints, expands as it freezes, then thaws. Each cycle pries the rock apart a little more until it fails.

The mechanical weathering process in which crystals that form from evaporating salt water exert pressure in cracks and pry apart rock fragments.

The weathering process in which sheets of granite separate from the main body as a result of pressure release

The process that creates sheeting, occurring when erosion removes material around rocks that crystallized under pressure

A granite dome formed through the process of sheeting

Weathering that occurs as a result of a chemical process

The chemical weathering process in which minerals dissolve in a liquid, usually water

A chemical reaction in which oxygen combines with a cation, changing the identity of a mineral

A chemical reaction in which hydrogen ions, usually from water, replace the cations in a mineral structure

A loose collection of minerals with a mica-like sheet structure produced by the chemical weathering of feldspars and/or amphiboles

The weathering process in which less resistant minerals wear away first, leaving more resistant minerals behind

The process that produces rounded rocks and boulders as a result of the increased weathering of edges and corners

The layer of rock and mineral fragments, including soil, lying above the unweathered bedrock

Chemical elements that naturally occur in minute concentrations, usually less than 0.1 percent of the rock or soil

The dynamic interface between inanimate rock and life containing regolith, humus, water, and air

The accumulation of decayed organic material found in the top layers of soil

A cross section of soil exposing soil horizons

A soil layer

The top layer of a soil profile; contains an accumulation of plant and other organic material in the process of decomposing

The second layer of a typical soil profile; contains humus and is part of the topsoil; also called the zone of leaching because of the transport of minerals dissolved in this layer

The O and A horizons in a soil profile containing the organic material in a soil

Another name for the horizon where leaching begins, dissolving minerals and transporting them downward to the B horizon

The third layer in a typical soil profile; also called the zone of leaching because water carries particles and dissolved minerals away from this layer

The transport of fine mineral particles to lower soil horizons

The fourth layer in a typical soil profile; also called he zone of accumulation because eluviated particles and dissolved minerals accumulate in this horizon

The B horizon in a soil profile

Another name for the B horizon in which dissolved minerals and eluviated particles accumulate

The lowest layer in a typical soil profile; contains rock fragments from the bedrock below

The rock and minerals fragments and particles from which soil develops

A well-developed soil containing significant amounts of organic matter

A soil that does not have a well-developed soil profile, because of lack of time or supportive environmental conditions

Weather that is averaged over a long period of time, usually 30 years

The state of the atmosphere with respect to various conditions, such as temperature, wind, clouds, moisture, and air pressure

Soil formed from local "in place" parent material

Soil formed from parent material formed elsewhere and later deposited at the current site

A soil classification system developed by the U.S. Department of Agriculture

A major soil type found in wet climates and containing large amounts of aluminum and iron

A major soil type found in dry climates containing large amounts of calcium

A soil type found in arid regions and characterized by the lack of development of soil horizons

A soil type found in tropical regions and characterized by thin O and A horizons, and virtually no B horizon

A reddish clayey material that forms the A horizon of tropical soils and that hardens in the sun; often used as building material of aluminum and iron

The downslope movement of earth materials

A force that acts on the material in a slope to move materials in a slope to move downhill, specifically gravity

A factor that impedes the movement of the materials in a slope from moving downhill

The resistance that occurs when one object moves over another

The tendency of particles of substance to stick together as a result of intermolecular forces

A slope that is likely to fail in the foreseeable future

A slope that is not likely to fail in the foreseeable future

The angle at which a slope is stable based on the properties of the materials composing the slope

A substance introduced between two moving surfaces to reduce friction and cohesion

The tendency of an object to stay at rest or of an object that is moving to continue to move, unless and outside force is applied

An event that upsets the balance between gravity and resisting factors, causing the slope to fall

The removal of the lower portion of a slope by erosion or construction, eliminating support for the upper portion of a slope

A free-falling, vertical or near-vertical downward movement of slope materials

A fall containing a rock or rocks falling as individual units

An accumulation of rock debris that rests against the face of a slope

A type of fall in which snow, rocks, or debris tumble down a face, picking up speed and more material as the material moves downward

The movement of a mass of earth materials down a diagonal slope

A sudden downslope movement of rock

A sudden downslope movement consisting of unconsolidated debris

A downslope movement of earth materials that rotate to form a curved surface, curved scarp, and stepped appearance

A downward movement of material mixed with water to form a mud or slurry

A flow of mud, usually down a stream valley

A flow containing debris and most often occurring after heavy rains on barren slopes

A flow of loose materials and water underneath a layer of sod

Composed of mounds or knolls

A flow that occurs under sod and over frozen layers of a slope

A very slow type of downward earth movement caused by successive wet/dry or freeze/thaw cycles

Terracing of a slope to change its angle of repose

Wire or mesh baskets filled with concrete or rock fragments and used to build retaining walls

A wall built to support an unstable slope

Any of a number of devices, typically buried in the ground, that extend from the backside of a retaining wall to act as anchors

An envelope of water that surrounds the earth and does not include water contained in rocks, the biosphere, or the atmosphere

A depression in the lithosphere filled with ocean water

A large body of saline water that fills an ocean basin

Water that lacks significant amounts of dissolved solids

The continuous exchange of water between the ocean and land

Energy released by the sun as heat and light

The process by which water is released by plants

The combined processes of evaporation and transpiration

The source of the stream

A stream and river that flows into a larger river

The geographical area drained by a stream or river

The high ground separating one drainage basin from another

The stream pattern that resembles the veins of a leaf

A drainage pattern that follows a well-developed rectangular fracture pattern in the bedrock

A drainage pattern resembling a trellis typical of regions with long ridges and valleys

A drainage pattern typical of a dome area and resembling the spokes of a wheel

A drainage pattern that runs around the bottom of a dome like a ring

A drainage patter resembling the spokes of a wheel in which the streams drain into the center of the pattern

A drainage pattern in which the draining streams run parallel to one another, equally spaced apart

A drainage pattern in which the stream breaks into intertwining smaller streams

The height times the width of a stream channel, multiplied by a one-foot or one-meter depth of the cross section

An even in which increased discharge of a stream or river causes it to overflow its banks

The speed of a volume of water passing a fixed poin

The "dip" of a river; its rate of descent

The smoothness or roughness of the stream channel

A smooth flow of water in which all particles are moving in the same direction

A chaotic flow of water in which particles move in various directions, creating eddies

A very thin layer of laminar flow where water makes contact with the stream channel

The downward erosion of the stream channel

The lowest elevation at which the stream can flow; the ultimate base level is the elevation at the stream's mouth

The size of the largest particles a stream or river can carry

A drainage patter that follows a well-developed rectangular fracture pattern in the bedrock

The total load a stream or river can carry

The substances carried by a stream

Particles (usually clays and silts) that are thoroughly mixed with-but are not dissolved in- the water of a stream or river

Rocks, sand, and other large particles too heavy to mix with stream water

The jumping and rolling action of rocks and sand as they are carried downstream

Dissolved salts and minerals carried by a stream or river

Sediment deposited by a stream or river

Of or found in a stream, such as a fluvial deposit

The narrow valley cut by a young stream; a canyon

Erosion that wears away land toward the head of a stream

Deep, circular depression worn into rock by an eddy or whirlpool of a turbulent stream

The winding turns of a river as it flows down a valley

The straight section of a meandering stream between bends

The outside bank of the curve in a river

The inside band of a curve in a river where sediment deposits

The area covered when a river floods, built up by sediment deposition in repeated events

A stream separated from the mains stream by levees and flowing in a nearly parallel direction

An accumulation of sand-sized particles deposited along a stream channel

A stream separated from the main stream by levees and flowing in a nearly parallel direction

The triangle-shaped region at the mouth of some rivers, formed by deposition of silts and clays.

A sudden local flood, often caused by heavy rain

A flood with a water level that has a two percent chance of occurring in any given year

A flood with a water level that has a one percent chance of occurring in any given year

Some 97% of the water on Earth's surface is contained in the ocean. The other 3% is freshwater

Slightly more than 74% of Earth's freshwater is frozen in glaciers

1. Atmosphere 2. Groundwater

How water moves between land and ocean. Evaporation to water vapor; condenses and precipitation falls. If it falls on the ocean, cycle is complete. If on land, water begins to flow back to the ocean. On the way could evaporate or be released by plants.

1. dendritic-stems of leaf 2. trellis-parallel valleys located between parallel folds;flow down slopes on both sides of divide 3. rectanular-underlying rock has rectangular fracture pattern of joints or faults and follows fractures 4. radial- domal uplifting, run off as spokes 5.annular-ring 6.reversed radial-down to center sinkhole

Discharge is the measurement of a stream's energy. 1. Volume-width and depth 2. Velocity-gradient and texture

Laminar-parallel: less energy and larger particles settle out Turbulent-change directions vertically and horizontally: more energy and can pcik up and transport larger particals

1.bed load 2. dissolved load: increase toward mouth of stream 3. suspended load: more variety at head downstream larger particles settle

sinuous twisting and turning of a river's course. Erosion on outside bank of turn and depostion on inside. Meander migrates side to side, widening the river valley and filling it with sediment. Migrates downstream, leaving behind features such as oxbow lakes

The mouth of a stream or river is where the velocity of the water slows enough for fine silts and clays to settle out and accumulate. They do so in the triangular patter characteristic of deltas

Mass wasting is the downward movement of the material composing a slope

gravity, which applies a downward force on slope materials

Friction, cohesion and the strength of materials

Stable: resisting factors exceed the force of gravity, making it unlikely to fail Unstable: resisting factors are almost the same as the force of gravity, making it likely the slope will fail when trigger occurs

A trigger is something that tips the balance between the driving force, gravity, and resisting factors to set slope movement in motion

Mass wasting features are usually named after the type of material in motion, the angle and speed of the movement, and the amount of water present.

An avalanche is a type of fall in which the materials are snow, rock, and debris. As a fall, the materials in the avalanche move in a vertical or near vertical path. A landslide involves materials that move along a plane at an angle that is less than vertical

A landslide moves along a plane, whereas the materials in a slump rotate, resulting in a curved path and curved scarp

A lahar is considered a type of mudflow. It occurs when the ash from a volcano mixes with meltwater from a glacier capping and erupting volcano, and rushes down the volcano's stream valleys

The slowest type of mass wasting is a creep, whose movement is not perceptible and is evident only in its effect on plants, poles, and other objects.

It is a map produced by the U.S. Geological Service that describes the likelihood of a mass-wasting event in the areas covered by the map

Cracks in roads, concrete walls, and foundation; a hummocky ground surface; other evidence of past mass-wasting events; tilted trees or poles; and undercutting are all indications that a mass-wasting even may occur in the foreseeable future.