15. Weathering And Mass Movement

Question 1

weathering

Answer 1

process by which solid rock is dissolved and broken apart into smaller fragments

Question 2

erosion

Answer 2

transport of rock fragments by moving water, ice, or air

Question 3

denudation

Answer 3

the lowering and wearing away of earth’s surface

Question 4

physical weathering

Answer 4

the breakdown of rocks into smaller pieces, or clasts, without altering the chemical makeup of the rock

Question 5

exfoliation

Answer 5

physical weathering process in which joints form parallel to a rock surface, creating sheetlike slabs of rock

Question 6

frost wedging

Answer 6

physical weathering process in which water trapped in an opening in a rock freezes and expands, causing the opening to grow

Question 7

salt wedging

Answer 7

physical weathering process in which salt crystals grow in pore spaces on a rock’s surface and dislodge individual mineral grains within the rock

Question 8

tafoni

Answer 8

pits or cavities on the surface of a rock that form through salt wedging

Question 9

root wedging

Answer 9

a physical weathering process in which plant roots break rocks apart

Question 10

chemical weathering

Answer 10

a process that changes the minerals in a rock through chemical reactions involving water

Question 11

differential weathering

Answer 11

unequal weathering across a rock surface

Question 12

karst

Answer 12

an area dominated by the weathering of carbonate rocks, usually limestone

Question 13

sinkhole

Answer 13

a depression in earth’s surface resulting from the weathering of carbonate rock underground

Question 14

sinkhole lake

Answer 14

a sinkhole that has filled with water

Question 15

collapse sinkhole

Answer 15

a sinkhole formed where the ceiling of a cavern has collapsed

Question 16

disappearing stream

Answer 16

a stream that leaves the ground surface and flows into subterranean channels

Question 17

speleothem

Answer 17

a cavern formation that forms by precipitation of calcium calcium carbonate

Question 18

stalactite

Answer 18

a speleothem that grows from the ceiling of a cavern downward

Question 19

stalagmite

Answer 19

a speleothem that grows from the floor of a cavern upward

Question 20

limestone column

Answer 20

a cylindrical speleothem resulting when a stalactite joins with a stalagmite

Question 21

mass movement

Answer 21

downslope movement of rock, soil, snow, or ice caused by gravity

Question 22

soil creep

Answer 22

the imperceptible downslope movement of soil and regolith as their volume changes in seasonal expansion-contraction cycles

Question 23

solifluction

Answer 23

a type of soil creep in which freeze-thaw cycles cause the soil to flow slowly downslope in overlapping sheets

Question 24

slump

Answer 24

a type of mass movement in which regolith detaches and slides downslope along a spoon-shaped failure surface and comes to rest more or less as a unit

Question 25

landslide

Answer 25

rapid movement of rock or debris down a steep slope

Question 26

mudflow

Answer 26

a fast-moving flow composed mostly of mud

Question 27

debris flow

Answer 27

a fast-flowing slurry of mud mixed with large objects, such as rocks and vegetation

Question 28

rock slide

Answer 28

a landslide that consists of rocks and broken rock fragments

Question 29

debris slide

Answer 29

a landslide that consists of a mixture of rocks, soil, and vegetation

Question 30

avalanche

Answer 30

a turbulent cloud of rock debris or snow that is mixed with air and races quickly down a steep slope

Question 31

rockfall

Answer 31

type of mass movement in which rocks tumble off a vertical or nearly vertical cliff face

Question 32

talus

Answer 32

pieces of angular broken rock that accumulate at the base of a steep slope or vertical cliff