Weathering Flashcards
Processes that occur within the surface of the earth such as weathering, erosion, volcanism, deposition, and mass wasting
Exogenic Processes
physical breakdown and chemical alteration of rocks and minerals at or near the earth’s surface
Weathering
agents of weathering
water, ice, acids, salt, plants, animals, temperature
types of weathering
mechanical, chemical, and biological
physical breakdown of a material without altering its chemical composition
mechanical weathering
when water accumulates in the crack and the ice freezes and breaks the rock apart
frost wedging
breakdown of rocks caused by impact and friction
abrasion
rocks have been shaped by blowing wind and sand
wind abrasion
water breaks into pieces from tumbling rocks
water abrasion
a process in which large flat or curved sheets of rock fracture and are detached from the outcrop due to pressure release
exfoliation
roots grow causing penetration into the crack, and break the rock
organic activity
human construction, mining, agricultural deforestation activities
biological activity
occurs in specific minerals which are dissolved in water. ex. Halite (NaCl) and Calcite (CaCO3). the formation of stalactites and stalagmites in caves are brought about by this chemical reaction
dissolution
rock-forming minerals like amphibole, pyroxene, and feldspar react with water and form different kinds of clay minerals
hydrolysis
causes rock to rust, or break down its layers
oxidation
factors of weathering
R - rock type
R - rock structure
T - topography
T - time
C - climate
moving broken material
erosion
material deposited in a new spot
deposition
wind, rain, and freezing break up rock
weathering
the movement of rocks and sediment from one place to another
erosion
agents of erosion
water, wind, ice, gravity
the wind picks up small pieces of rock fragments and carries them along until they reach an obstacle
wind erosion
a large body of moving ice that is caused by erosion
glacier
when a pile of rock falls down the side of the mountain as a single block
landslide
the cause of mountain peaks, valleys, and coastlines
erosion
when the water stops moving, when the wind stops blowing, when the glacier melts, when the rock has been dropped in a new location
deposition
when a river meets the ocean
mouth of the river
the land formed after soil gets carried by a river that is deposited at the mouth.
delta - water deposition
large deposits of sand caused by deposition that also shifts frequently
sand dunes
rocks and soil left behind by a melting glacier
moraine
downhill movement of earth’s material caused by gravity
mass wasting
most destructive. rock/soil slides quickly down steep slope
landslide
rapid movement of water, rock, soil
mudflow
a wedge of soil falling rather than a rock
slump
slow movement of soil down a slope
creep
contribute to mechanical weathering and describes all downhill movements of weathering material (also known as a landslide)
mass wasting
slope stability is determined by:
slope angle and strength of the underlying material
fs
the shear or driving force
fn
normal or resisting force
the relationship between fs and fn is called
shear strength
types of mass wasting
falls, rotational slides, translational, flows, and soil creep
abrupt rock movement that DETACH from cliffs (rolling, bouncing)
falls
SLOW MOVEMENT along a RUPTURED SURFACE
rotational slides
RAPID MOVEMENT along a STABLE UNDERLYING MATERIAL (rock slides, debris slides, earth slides)
Translational
loose material mixed with abundant water (debris & earth)
flows
very very slow adjustment of soil and rocks that is hard to notice
soil creep
