Arid region geomorphology...What causes the erosion and deposition?

- Wind, Water, and Gravity

Arid region geomorphology...What causes the erosion and deposition?

- Wind, Water, and Gravity

Badlands topography with terracesBadlands topography with terraces

Types of streams in Arid and semi-Arid locales

Exotic streams- begin in areas that are not arid and flow into the desert.

Ex. Nile River, Colorado River, Okavango River

Local streams (Arroyos) - begin in the arid region, and often end there as well.

There are many streams of this type…

Types of streams in Arid and semi-Arid locales

Exotic streams- begin in areas that are not arid and flow into the desert.

Ex. Nile River, Colorado River, Okavango River

Local streams (Arroyos) - begin in the arid region, and often end there as well.

There are many streams of this type…

A dry stream channel (arroyo)Note the scale of the bouldersA dry stream channel (arroyo)Note the scale of the boulders

Nile River-

An exotic stream

Nile River-

An exotic stream

Colorado River-Dammed

Alluvial fans & Bajadas in Death Valley Graben

Alluvial fans & Bajadas in Death Valley Graben

Playa lake,

Owens Valley,

CA

Sand Dunes in Colorado Great Sand Dunes National Monument

Star Dune in Mexico

Star Dune

Linear Dunes

With an exotic stream

windwind

Barchanoid dunes with smaller transverse & barchanoid dunes superimposed on themBarchanoid dunes with smaller transverse & barchanoid dunes superimposed on them

Transverse dunes in Namibia- oblique aerial view

Transverse dunes in Namibia- ground view

Barchan dunesBarchan dunes

Wind directionWind direction

Slip faceSlip face

Barchan dunesBarchan dunes

Wind directionWind direction

Parabolic dunes -on a topo mapParabolic dunes -on a topo map

Parabolic dunesParabolic dunes

Erosional landforms vs. Depositional landformsErosional forms include...

Pediment - bedrock ramp that leads up to the mountain front

Plateau- large flat undeformed area that is topographically higher than the

surrounding region

Mesa- Smaller than the plateau, but basically the same feature

Buttes- smaller than the Mesa, but basically the same feature

Spires (a.k.a. Hoodoos)- smaller than the buttes

Piedmont in Colorado

Piedmont is a geographic designation relating to the slope and or foothills leading to a mountain range

Piedmont in Colorado

Piedmont is a geographic designation relating to the slope and or foothills leading to a mountain range

Colorado Plateau with Grand Canyon

A Mesa

Buttes and Spires in Monument Valley, UtahButtes and Spires in Monument Valley, Utah

Spires, Hoodoos, goblins...Spires, Hoodoos, goblins...

Yardangs on Mars

Yardang

Boulders (foreground) collected from desert pavement (background)Boulders (foreground) collected from desert pavement (background)

Desert Pavement and Desert Varnish

Ventifact

ventifacts

Walking Boulders