Geomorphology Test 1 definitions
Terms
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- In situ decomposition of rocks and minerals
- Weathering
- Transport of weathered material
- Erosion
- most important factor that determines type of weathering
- Climate
- Two main types of weathering
- Physical and Chemical
- disintegration of rock without chemical changes
- Physical weathering
- chemical changes to the composition of a rock
- Chemical weathering
- 8 types of physical weathering
- Unloading, Freezing and Thawing, Hydrofracture, Crystal Growth, Thermal expansion and contraction, Wetting and Drying, Organic Activity, Gravitational impact
- disintegration of rock from changes in volume associated with pressure changes as the rock moves to the surface
- unloading
- Formed from unloading
- Sheeting joints and exfoliation domes
- large mound of granite
- exfoliation dome
- water seeping into rock and freezing expands 93%
- Freezing and Thawing
- formed by freeze, thaw and rock falls
- Talus
- Water pushed through rock by freezing water near the surface.
- Hydrofracturing
- block fields/ broken up boulders and cobbles
- Felsenmeres
- water percolating into rock and material, when it evaporates, crystals form
- Crystal Growth
- repeated heating and cooling
- thermal expansion and contraction
- WEtting and drying, shale disintegrates
- pedestal rocks
- mud stick to rock edge, after drying it pulls off rock grain
- colloidal plucking
- importance for chemical weathering
- surface area and water
- disruption of mineral in water into consistent ions and molecules
- dissolution
- largest cave in gypsum
- alabaster caverns, ok
- mineral loses electron to oxygen
- oxidation
- mineral gains electron
- reduction
- substituting one element for another without changing mineral structure
- ion exchange
- least mobile to most mobile elements
- Ca, NA, Mg, K, Si, T, Fe, Al
- chemical addition of H+ and OH- ions into structure of mineral to create a new mineral
- hydrolysis
- organic rings pluck off metal ions
- chelation
- mineral containing K, Na, Ca, Mg are changed to some sort of CaCO3 by cation of carbonic acids
- Carbonization
- addition of water into mineral structure to form a new mineral
- hydration
- formed from hydration
- anhydrite
- 6 types of chemical weathering
- dissolution, oxydation/reduction, ion exchange, hydrolysis, carbonization, hydration
- 9 controls of weathering
- availability of water, temp, pressure, circulation of water, parent material, vegetation, topography, aspect, time
- 5 dependents of weathering rates
- parent material, climate, vegetation, topography, time
- product of granular disintegration
- grus
- weathering of angular edges into rounded edges.
- spheroidal weathering
- bold, isolated outcrop that rises drastically from the ground and can be meters high
- tors
- caused by hydrolisis, honeycomb structure on side of cliffs
- cavernous weathering
- large scale tors
- inselburg
- broken up pieces of rock
- regolith
- ancient soil
- paleosol
- once stress is released it is turned back to original shape
- elastic
- once stress is released, it remains deformed
- plastic
- behaves like a fluid
- viscous
- point which a material no longer behaves elastically
- elastic limit
- amount of force required to cause failure
- strength
- breaking in direction to force
- shear strenth
- breaking on perpendicular plane
- tensile strenght
- collapsing in on itself
- compressive strength
- mechanical resistance to relative motion of adjacent masses
- friction
- slow and steady continuous plastic deformation
- crepe
- resistance to movement of 2 masses separated by a well defined plane
- sliding friction
- friction between internal grains
- internal friction
- shear strength not associated with inner particle strength
- cohesion
- porosity filled with water exerts pressure
- fluid pressure
- water dissolves minerals and transports them
- siddolution
- movement of material on the top of water
- floatation
- velocity keeping objects from settling
- suspension
- types of streams
- straight, anastomosing, braided, meandering
- river flows with the slope of the land
- consequent streams
- have no preferred direction
- insequent streams
- selective headward erosion following courses along weakness
- subsequent streams
- originally consequent stream, but has been modified to flow opposite direction
- obsequent streams
- obsequent stream flowing at original direction but at a lower level
- resequent
- types of drainage patterns
- dendritic, trellis, rectangular, radial, centripetal
- a leading edge of incision observed as a waterfall
- knickpoint
- drainage divide shifts so that one river's drainage captures another
- abstraction
- tributary captures the original, trunk stream
- autocapture
- old valley that is left high and dry due to stream capture
- wind-gap
- one meandering stream meanders into another
- intercision
- gently sloping, concave upward graded surface of erosion that cuts across rocks of varying resistance mantled with a thing veneer of alluvium
- pediment