chapter 16 weathering and mass movement Flashcards
weathering
the process by which solid rock is dissolved and broken apart into smaller fragments
erosion
the scouring and stripping away of rock fragments loosened by weathering
sediment transport
the movement of rock fragments that have been weathered and eroded
deposition
the depositing of sediments
denudation
the lowering and wearing away of earth’s surface
physical weathering
the processes that breaks rocks down into smaller pieces without altering the chemical makeup of the rock
exfoliation
a type of pressure release jointing, creates sheetlike slabs of rocks resembling the layers of an onion
frost wedging
the process by which water in a joint in rock freezes and expands, causing the opening to grow ex. potholes
salt weathering
the process in which salt crystals grow in pore spaces within a rock and exert pressure as they grow
tafoni
rounded pits or cavities on surface of a rock that form through salt wedging
root wedging
the process in which plant roots break rocks apart
chemical weathering
the process in which minerals in rock change through chemical reactions involving water
carbonation
a chemical weathering process in which carbonate rocks such as limestone is dissolved in a carbonic acid solution and carried away
hydrolysis
the process in which water reacts with and combines with minerals in rocks to form new minerals
oxidation
the process in which oxygen atoms combine with minerals in rocks and weaken them
hydration
the process in which water is added to minerals in rock or soil, causing material to expand and weaken
spheroidal weathering
the process where angular blocks experience the most weathering along their edges and corners, causing them to become rounded
differential weathering
unequal weathering across a rock surface
karst
an area dominated by the weathering of carbonate rocks, usually limestone
dissolution
the general process in which a mineral completely dissolves in water
sinkhole
a depression in earths surface that results from the dissolution of carbonate rock underground
collapse sinkhole
sinkhole formed where ceiling of a cavern has collapsed
disappearing stream
streams that disappear into subterranean channels in karst regions
speleothem
cave formation that forms by precipitation of calcium carbonate
stalactite
speleothem that grows from the ceiling of cave downward
stalagmite
speleothem that grows from floor of cave upward
limestone column
cylindrical speleothem resulting when a stalactite joins with a stalagmite
dripstone vs flowstone
dripstone- speleothem that are formed by precipitation of calcium carbonate by dripping water
flowstone- sheetlike calcium carbonate deposits that form along the edged that water drops flow down before they drip
mass movement
movement of rock, soil, snow, or ice downslope by gravity
factors that make slopes unstable
- geologic faults
- jointing in rocks
- foliation planes in metamorphic rock
- layers of saturated clay and sand
- layers of ice between snow layers
rockfall
occurs when rocks tumble off a vertical or nearly vertical cliff face
talus
pieces of angular broken rock that accumulate at the base of a steep slope or vertical cliff
talus cone
an accumulation of talus in cone shaped piles at the base of rockfall chutes
talus apron
an accumulation of talus that forms where two or more talus cones merge at the foot of a cliff
