Geomorphology Flashcards
Landslides
A large mass of land breaks loose and plunges down a slope
Rockfalls
Tock fragments fall to the bottom of the slope
Mudflow
Streams of mud flow down a steeper slope in definite channels
Soil creep
A very slow continuous movement of soil down a slope
Solifluction
Top soil becomes saturated and slides on the frozen ground beneath it
Earthflow
Occurs when clay soul particles, saturated with water, move down a slope with a fairly gentle gradient
Mass movements
Downward movement if weathered materials such as soil, stones and rocks on a slope as a result of the force of gravity
Peneplain
A nearly flat plain formed by erosion of slopes in a humid environment
Down wasting
Erosion of the land mass in such a way that landforms become lower over time
Pediplain
A nearly flat plan formed as canyon floors become wider, usually in an arid environment
Back wasting
Erosion of the land mass in such a way that landforms become narrower
Parallel retreat
Erosion of a scarp slope causes loss of ground over the whole face of the slope, but no loss of height
Sheetflow
Rainwater flows over a slope in a sheet
Crest
Small convex slope element at the top if the slope
Freeface
Slope element greater than 80* to the horizontal
Talus
Slope at the base of a hill consisting of weathered material
Scree
Weathered material at the base of the slope
Pediment
Slope element with a low angle, concave shape
Knickpoint
Sharp change in gradient
Endogenic forces
Forces operating deep underground, folding
Exogenic forces
Forces operating above the Earth’s surface, erosion and deposition
Primary slopes
Slopes formed by crustal forces, faulting
Primary erosion slopes
Slopes which have formed from erosion, a gorge eroded by a river
Secondary erosion slopes
Primary slopes or primary erosion slopes that have been eroded
Tor
Exposed granite blocks made up of core stones
Core stones
Granite boulders left after surrounding rock has weathered
Granite dome
Landform resulting from erosion of overlying strata to expose a batholith
Exfoliation
The peeling off of rock layers due to expansion and contraction
Contractual joins
Joints formed when magma cooled
Off-loading joints
Joints formed when the weight of overlying material is removed
Batholiths
Large dome-shaped intrusions of magma which occur at great depths beneath the Earth’s surface
Laccoliths
Smaller mushroom-shaped intrusions of magma
Lopoliths
Pan or saucer-shaped intrusions
Dykes
Vertical sheets of dolerite that form magma
Sills
Horizontal layers of dolerite that form magma
Poort
Gap between two mountains which has been created by river erosion
Cuesta dome
Circular or oval-shaped landform from the erosion of an anticline
Cuesta basin
Circular or oval- shaped landform resulting from the erosion of a syncline
Cuesta
A ridge with a gentle slope and a scarp slope
Hogsback
A ridge with a steep slope and a scarp slope
Homoclinal ridge
Ridge formed from inclined strata
Homoclinal landscape
A landscape formed of inclined strata that are tilted by the same degree of dip in the same direction
Scarp slope
Steep slope of a homoclinal ridge or escarpment
Dip slope
Less steep slope of a homoclinal ridge
Mass wasting
Movement of eroded material downhill due to gravity
Undercutting
Erosion of a rock at the base of a slope with the subsequent collapse of the overhang
Homoclinal shifting
Movement of the position of a homoclinal ridge towards the dip slope
Chemical weathering
Decomposition of rock due to chemical precessess, often involving water, CO2 and O2
Mechanical weathering
The physical break-up of rocks, often due to extremes in temperature
Scarp retreat
Erosion of scarp slope causes loss of ground over the whole slope, but no loss of height
Pediplain
Large, low-angled plain
Conical hills
Small pointed hills
Pointed buttes
Narrow hills with a sharp peak at the top
Buttes
Flat-topped hills with a greater height than width
Mesas
Flat topped table mountains with a greater width than height
Cap rock
Horizontal layer of hard, resistant rock at the top of the mountain
Tectonic uplift
Rising of land mass due to crustal forces
Gullies
Small, narrow, long areas of erosion on a slope
Badlands
A landscape with narrow gullies and sharp ridges formed in arid climates
Sedimentary rock
Rock formed from the deposition and consolidation of eroded sediments
Plateau
Large high-lying area that is relatively flat
Igneous rock
Rock formed when magma cools and solidifies
Landscapes
Area with a number of landforms
Dolerite sill
A horizontal layer of igneous rock that has formed along a bedding plane
Lava flow
Lava pours out onto the Earth’s surface where it cools and becomes solid
Bedding planes
Planes separating layers of rock
Stratified rock
Rock composed of layers or strata