Drylands- Mid latitude desert: Colorado Plateau and Death Valley

Question 1

background info

Answer 1

SW USA, 34-40 lat, btw Rocky Mountains and Great Basin

Question 2

physical aspects

Answer 2

180mm/yr, -4 - 34C, drainage only from Colorado River which water is from Rockies snowmelt

Question 3

geomorphic processes

Answer 3

weathering, mass movement, fluvial action. freeze-thaw in winter, salt weathering and insolation important but affected by low rain. rock falls and slides frequent on cliffs, occasional torrential rain flash floods

Question 4

main landforms

Answer 4

pediments, screes, buttes and mesas, canyons and ravines

Question 5

formation of pediments

Answer 5

gently sloping rock platforms in Monument Valley formed with retreat of buttes and mesas, covered by superficial layer of sediment transported by ephemeral streams

Question 6

mesas and buttes

Answer 6

the plateau was once constant but has been reduced to flat top inselbergs, the bigger ones are inselbergs and the smaller buttes. weathering on side sandstone causes rockfalls and scree slopes at foot, top is flat due to resistant caprock

Question 7

canyons and ravines

Answer 7

rivers cut deep canyons like Grand Canyon, over Ms of yrs tectonic plates lifted plateau letting rivers cut to make much deeper canyons

Question 8

landscape system changes

Answer 8

long term like lifting to create canyons, remains of plateau in Monument Valley are scattered inselbergs that will disappear with only significant rockfall every few centuries, small particles from freeze thaw add to scree in shorter time, minor rockfalls after heavy rain