definition - less than 25 cm of rain each year; weathering is slower than in other environments - mountains more jagged and rugged
Distribution: 20-30 latitude, distance from ocean, rainshadow
Erosion
water: little vegetation makes erosion easy
wind: abrasion can play a major role and sculpt rocks, ventifacts; deflation, desert pavement
Transport
water: ephemeral streams periodically
carry large sediment load due to lack of vegetation
wind: low competence but high capacity - often moves sediment through saltation
Deposition
water: ephemeral braided streams; alluvial fans;
playa lakes, evaporites
wind: sand dunes - cross-bedding, dune
migration; barchan dunes, transverse dunes,
longitudinal dunes, parabolic dunes
Landscapes
erg desert, Colorado Plateau, butte, mesa, plateau; Basin and Range
Describe 3 factors that control the distribution of deserts.
Explain how the process of deflation forms desert pavement.
What are
ventifacts and how do they form?
How do dunes migrate? Why? What is the slip face and how does
it relate to cross-bedding?
Compare and contrast barchan dunes, transverse dunes,
longitudinal dunes, and parabolic dunes in terms of shape, location,
and mechanism of formation.
Compare and
contrast the two major American desert landscapes.