XIII. Deserts

1. characteristics
1. low rainfall, but violent
2. mostly mechanical weathering with much wind influence
3. little soil and little vegetation
4. impermeable serfaces
5. interior drainage
2. types
   1. ergs
   2. regs
   3. hamadas

1. erosion
   1. flash floods - ephemeral streams
   2. differential erosion - inselbergs
2. deposition (fig. 18-26)
   1. playa lake and salt flat (fig. 18-27)
   2. alluvial fan (fig. 18-28, 18-14, 18-G)

1. erosion
   1. abrasion - usually near ground surface
   2. deflation - removal of fine material (dust and some sand)
      • blowouts
      • desert pavement (fig. 18-16)
2. Deposition
   1. sand dunes
      • slip face - angle of repose
      • dune migration (fig. 18-19)
      • types of dunes (fig. 18-20)
        • barchans (fig. 18-21)
        • seifs (fig. 18-22)
        • transverse

1. mesa and scarp (fig. 18-33)
   1. pillar
   2. butte
   3. mesa
   4. plateau
2. Basin and Range (fig. 18-26)