Geol 101 - 2nd Exam Review - 2005
Terms
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- creep
- very slow, downslope movement of soil or unconsolidated debris
- debris
- any unconsolidated material at Earth's surface, such as soil and rock fragments
- debris avalanche
- a rapidly moving, turbulent mass of debris, air, and water
- debris flow
- mass wasting in which motion is taking place throughout the moving mass
- debris slide
- a coherent mass of debris moving along a well-defined surface
- earthflow
- debris that moves downsloap as a viscous fluid
- landslide
- a slow to a very rapid descent of rock or soil
- mass wasting
- (mass movement) movement in which bedrock, rock debris, or soil moves downslope in bulk because of the pull of gravity
- permafrost
- ground that remains frozen for many years
- relief
- the vertical distance between valley floor and mountain summit
- rockslide
- the rapid sliding of a mass of bedrock along an inclined surface of weakness
- rotational slide (slump)
- movement along a curved surface - the upper part moving downward while the lower part moves outward
- shear force
-
-parallel to the slope
-indicates the rock's ability to move - slide
- -means the descending mass remains relatively intact moving along one or more well-defined surfaces
- soluifluction
- the flow of water-saturated debris over impermeable material
- talus
- an apron of fallen rock fragments that accumulate at the base of a cliff
- translational slide
- the descending mass moves along a plane approx parallel to the slope of the surface
- abrasion
- the grinding away of the stream channel by the friction and impact of the sediment load
- alluvial fan
- a large, fan or cone shaped pile of sediments that usually forms where a stream's velocity decreases as it emerges from a narrow mountain canyon onto a flat plain
- bar
- a ridge of sediment, usually sand and gravel, deposited in the middle or along the banks of a stream
- base level
- -the limit of erosion of the earth's surface
- bed load
- the large or heavy sediment particles that travel on the stream bed
- braided stream
- flowing in a network of interconnected rivulets around numerous bars
- delta
- a body of sediment deposited at the mouth of a river when the river's velocity decreases
- dendritic pattern
-
-a drainage pattern that resembles branches of a tree or nerve dendrites
-develop on uniformly erodible rock or regolith and are the most common pattern - discharge (of a stream)
- the volume of water that flows past a given point in a unit of time
- dissolved load
- soluble products of chemical weathering processes
- distributaries
- small, shifting channels that carry water away from the main river channel and distribute it over the surface of the delta
- divide
- a rich or strip of high ground dividing one drainage basin from another
- downcutting
- the process of deepening a valley by erosion of the stream bed
- drainage basin
- the total area drained by a stream and its tributaries
- drainage pattern
- reveals the nature and structure of the rocks underneath a river
- flood plain
- a broad strip of land built up by sedimentation on either side of a stream channel
- graded stream
- one that exhibits a delicate balance between its transporting capacity and the sediment load available to it
- headward erosion
- the slow, uphill growth of a valley above its original source through gullying, mass wasting, and sheet erosion
- hydraulic action
- the ability of flowing water to pick up and move rock and sediment
- hydrologic cycle
- the movement of water and water vapor from the sea to the atmosphere, to the land, and back to the sea and atmosphere again
- incised meanders
- meanders that retain their sinuous pattern as they cut vertically downward below the level at which they originally formed
- lateral erosion
- the erosion and undercutting of a stream's banks and valley walls as the stream swings from side to side across its valley floor
- meander
- sinuous curve
- meander cutoff
- a new, shorter channel across the narrow neck of a meander
- natural levees
- low ridges of flood deposited sediment that form on either side of a stream channel and thin away from the channel
- oxbow lake
- the cutoff meander becomes a crescent-shaped lake that may fill with sediment and vegetation
- point bar
- a type of sand bar deposited on the inside of curves because of lower velocity there - usually consist of arcuate ridges of sand or gravel
- pothole
- depressions that are eroded into the hard rock of a stream bed by the abrasive action of the sediment load
- radial pattern
-
a drainage pattern in which streams diverge outward like spokes of a wheel
-they form on high conical mountains like volcanoes and domes - rectangular pattern
- a drainage pattern in which tributaries have frequent 90 degree bends and tend to join other streams at right angles
- saltation
- when sand grains move by traction downstream in a series of short leaps or bounces off the bottom
- sheetwash
- a thin layer of unchanneled water flowing downhill
- solution
- gradual dissolving of the rocks in a stream channel
- stream
- a body of running water that is confined in a channel and moves downhill under the influence of gravity
- stream channel
- a long, narrow depression eroded by the stream into rock or sediment
- stream gradient
-
the downhill slope of the bed
-controls a stream's velocity - stream terrace
- steplike landforms found above a stream and its flood plain
- stream velocity
- the distance water travels in a stream per unit of time
- superposed stream
-
-shows the origin of mountain ranges that have steep-sided river valleys slicing directly across them
-and old river could have been there and eroded the mountain - suspended load
- sediment that is light enough to remain lifted indefinitely above the bottom by water turbulence
- traction
- movement by rolling, sliding, or dragging
- trellis pattern
- drainage pattern that consists of parallel main streams with short tributaries meeting them at right angles
- tributary
- a small stream flowing into a larger one
- aquifer
- a body of saturated rock or sediment through which water can move easily
- artesian wall
- a well in which the leve of water is above the top of the aquifer
- cave (cavern)
-
a natuarally formed underground chamber
-they usually form when slightly acidic ground water disolves limestone along the joints and bedding planes - concretion
- a hard rounded mass that developes when a considerable amount of cementing material percipitates locally in a rock
- confined (artesian) aquifers
- confined aquifers
- drawdown
- local lowering of the water table
- gaining streams
-
-found mostly in rainy regions
-receive water from the saturated zone
-the surface of these streams coincides with the water table - geode
- partly hollow, globe-shaped bodies found in some limestones and locally in other rocks
- geyser
- a type of hot spring that periodically erupts hot water and stream
- ground water
- the water that lies beneath the ground surface, filling the pore space between grains in bodies of sediment and clastic sedimentary rock, and filling cracks and crevices in all types of rock
- hot spring
- springs in which the water is warmer than human body temperature
- karst topography
- describes an area with many sinkholes and with a cave system beneath the land surface
- losing stream
-
-occur in drier climates
-streams that loose water to the saturated zone
-the channels of these streams lie above the water table - perched water table
- the top of a body of ground water separated from the main water table beneath it by a zone that is not saturated
- permeability
-
the capacity of a rock to transmit a fluid such as water or petroleum through pores and fractures
-measures the relative ease of water flow and indicates the degree to which openings in a rock interconnect - petrified wood
- a type of fossil that develops when porous buried wood is either filled in or replaced by inorganic silica carried in by ground water
- porosity
-
the percentage of rock or sediment that consists of voids or openings
-measures the rock's ability to hold water - recharge
- the addition of new water to the saturated zone
- saturated zone
- the subsurface zone in which all rock openings are filled with water
- sinkhole
- closed depressions found on land surfaces underlain by limestone
- speleothems
- deposits of calcium built up in caves by dripping water
- spring
- a place where water flows naturally from rock onto the land surface
- stalagmites
- cone-shaped masses of dripstone formed on cave floors, generally directly below stalacites
- stalacites
-
icicle-like pendants of dripstone hanging from cave ceilings
-generally slender and are commonly aligned along cracks in the ceiling
-act as conduits for ground water - unconfined aquifer
- has a water table because it is only partly filled with water
- vadose zone
- the zone above the water table that is generally unsaturated
- water table
- the makrs of a well on the upper surface of the saturated zone
- well
- a deep hole, generally cylindrical, that is dug or drilled into the ground to penetrate an aquifer within the saturated zone
- ablation (wastage)
- when glacier ice moves downward and is eventually lost due to gravity
- advancing glaciers
- glaciers with positive budgets push outward and downward at their edges is one
- alpine glaciation
- types of glaciers found in mountainous regions
- continental glaciation
- a large part of a continent is covered by glacial ice
- arete
- sharp ridges that separate adjacent glacially carved valleys
- basal sliding
- the sliding of a glacier as a single body over the underlying rock
- cirque
- a steep-sided, half-bowl shaped recess carved into a mountain at the head of a valley carved by a glacier
- crevasses
- open fissures that develop within glaciers
- drumlin
-
bodies of till shaped into streamlined hills
-shaped like an inverted spoon aligned parallel to the direction of ice movement of the former glacier - end moraine
- a ridge of till, piled up along the front edge of ice
- equilibrium line
- marks the highest point at which the glacier's winter snow cover is lost during a melt season
- erratic
- an ice-transported boulder that has not been derived from underlying bedrock
- esker
- an outwash feature of unusual shape associated with former ice sheets and some very large valley glaciers
- fiord
-
a coastal inlet that is a drowned glacially carved valley
-common along mountainous coastlines - glacier
- a large, long-lasting mass of ice, formed on land that moves under its own weight
- ground moraine
- a thin, extensive layer or blanket of till
- hanging valley
- after glaciers disappear, tributaries are left high above the main valley
- horn
- the sharp peak that remains after cirques have cut back into a mountain on several sides
- icebergs
- blocks of ice that break free from glaciers and float in a body of water
- ice cap
- a small layer of ice covering a smaller piece of land
- ice sheet
- a mass of ice that is not retricted to a valley but covers a large area of land
- kettle
- a depression in land that forms after an ice block melts
- lateral morains
- elongated, low mounds of till which form along the sides of a valley glacier
- moraines
- till that occurs as a body of unsorted and unlayered debris either on a glacier or left behind by a glacier
- medial moraine
- the long ridge of till in between to adjacent lateral moraines
- outwash
- the material deposited by the debris-laden meltwater
- plastic flow
- slowly flowing glacial ice (like molasses)
- pluvial lake
- lakes formed in a period of abundunt rainfall
- receding glaciers
- glaciers with negative budgets that grow smaller and their edges melt back
- rigid zone
- the upper part of the glacier
- rock-basin lake (tarns)
-
lakes that usually form a chain after ice has melted
-form depressions in weaker rock - rock flour
-
composed largely of very fine particles of unaltered minerals
-produced by the grinding of rock across rock - terminus
-
the lower edge of a glacier
-moves farther downvalley when a valley glacier has a positive budget
-sometimes it melts back upvalley - theory of glacial ages
- states that at times in the past, colder climates prevailed during which much more of the land surface of earth was glaciated than at present
- till
- the unsorted and unlayered rock debris carried or deposited by a glacier
- tillite
-
lithified till
-shows evidence of older glaciation - truncated spur
- ridges that have triangular facets produced by glacial erosion at their lower ends
- u-shaped valley
- characteristic of Glacial Erosion
- v-shaped valley
- characteristic of Stream Erosion
- valley glacier
- glacier that is confined to a valley and flows from a higher to a lower elevation
- varve
- two layers of sediment representing one year's deposition in a lake
- zone of ablation
- the lower part of a glacier where ice is lost, or ablated, by melting, evaporation, and calving
- zone of accumulation
- part of the glaciar with a perennial snow cover
- bajada
-
a broad, gently-sloping depositional surface formed by the coalescing of individual alluvial fans
-very extensive with a gently rolling surface - barchan
- a crescent-shaped dune with a steep slip face on the inward or concave side
- blowout
- a depression on the land caused by wind erosion
- butte
- a narrow hill of resistant rock with a flat top and very steep sides
- deflation
- the removal of clay, silt, and sand particles from the land surface by wind
- desert
- any region with low rainfall
- fault
- a crack in the soil along which some rock movement has taken place
- flash flood
-
sudden local floods of high discharge and short duration
-more common in arid regions than in humid regions - loess
- a deposit of wind-blown silt and clay composed of weathered, angular grains of quartz, feldspar, and other minerals weakly centered by calcite
- longitudinal dune
-
-one of the largest types of dunes
-symmetrical ridge of sand that forms parallel to the prevailing wind direction - mesa
- a broad, flat-topped areas elevated above the surrounding land and bounded by cliffs and capped with a resistant rock layer
- plateaus
- broad, flat-topped areas elevated above the surrounding land and bounded, at least in part, by cliffs
- playa
- a very flat surface underlain by hard, mud-cracked clay
- playa lake
- very shallow lakes created by runoff water in desert areas
- pediment
-
a gently sloping surface created by erosion of a mountain
-it is commonly covered with a veneer of gravel, cut into the solid rock of a mountain - rain shadow
- as moist air is forced up to pass over a mountain range, it expands and cools,loosing moisture as it rises
- sand dune
-
mounds of loose sand grains heaped up by the wind
-mostly develop in areas of very strong winds - slip face
- the steep downwind slope of a dune
- transverse dune
- a relatively straight, elongated dune oriented perpendicular to the wind direction
- ventifact
- rocks with flat, wind-abraded surfaces
- arch
- bridges of rock left above openings eroded in headlands or stacks by waves
- barrier islands
- ridges of sand that parallel the shoreline and extend above sea level
- baymouth bar
- a ridge of sediment that cuts a bay off from the ocean and is formed by sediment migrating across twhat was earlier an open bay
- beach
- a strip of sediment that extends from the low-water line inland to a cliff or a zone of permanent vegetation
- beach face
- the steepest part of the beach which is exposed to wave action, particularly at high tide
- berm
- a wave-deposited sediment platform that is flat or slopes slightly landward
- breaker
- a wave that has become so steep that the crest of the wave topples forward, moving faster than the main body of the wave
- coast
- all the land near the sea, including the beack and a strip of land inland from it
- coastal straightening
- takes place on an irregular shore gradually by wave erosion of headlands and wave deposition in bays
- crest (of wave)
- the high point of a wave
- trough
- the low point of a wave
- estuary
- a drowned river mouth
- headland
- points of land that stick out of a coast next to bays
- longshore current
-
a moving mass of water that develops parallel to shoreline
-its width is equal to the width of the surf zone - longshore drift
- the movement of sediment parallel to shore when waves strike the shoreline at an angle
- marine terrace
- a broad, gently sloping platform that may be exposed at low tide if the shore has significant tidal action
- rip current
- narrow currents that flow straight out to see in the surf zone, returning water seaward that breaking waves have pushed ashore
- sea cliffs
- steep slopes that retreat inland by mass wasting as wave erosion undercuts them
- spit
- a fingerlike ridge of sediment that extends out into open water
- stack
- erosional remnants of headlands left behind as the coast retreats inland
- wave height
- the vertical distance between the crest and the trough
- wavelength
- the horizontal distance between two wave crests or two trophs
- surf
- breakers - or waves that become so steep that the crest of the wave topples forward
- wave refraction
- the bending of a wave as it slows progressively along its length and changes direction and becomes more nearly parallel to the shoreline
- tombolo
- a bar of sediment connecting a former island to the mainland