Desert Landforms Flashcards
(23 cards)
Where are parabolic dunes located?
Peru
Where are star dunes located?
Namib Desert
Where are Barchan Dunes located?
New Mexico
Where are Yardangs located?
Boukou region in Chad
Where are Wadis located?
loads of good places, eg Wadi Rum in Jordan
Where are alluvial fans located?
Death valley, California
Where are Arroyos located?
Arroyo Chico, Tucson, Arizona
Where are Pediments located?
Base of Santa Catalinas in Tucson, Arizona
Where are Bahadas located?
Verdugo Mountains, North Glendale, California
Where are Playas located?
lake chad, Chad
Where are Salt Lakes located?
Great Salt Lake, Utah
Where are Inselbergs located?
Mirabib inselberg, Namibia
How do Parabolic Dunes form?
- unidirectional Wind
- some kind of stabilising factor at the limbs, usually vegetation
- so n shape (from Windward direction) created as windward side pushed back and sand deposited on leeward side
How do star dunes form?
- multidirectional winds
- sometimes seasonal
How do Barchan dunes form?
- unidirectional wind
- limited sand supply
- so horns pushed further faster, so U shape from Windward direction
How do Yardangs form?
vertical Columns of hard and soft rock, soft erodes more quickly
How do Zeugens form?
Horizontal Rows of harder and softer rock, once bit of soft rock is exposed more and more erdodes, creating yardangs like shape
How do Wadis/arroyos form?
1.water erosion on small river path over time
2. sometimes pleistocene Pluvials when wadi too big
How do alluvial fans form?
- Stream of water exits a defined channel, usually because gradient is lower
- so more energy lost, so load deposited
How do pediments form?
- sheetwash erosion of slope, changing gradient,
- usually covered by thin veneer of sediment
How do bajadas form?
series of coalescing alluvial fans
How do Playas and Salt lakes form?
- form in depressions, (eg deflation of tectonic activity)
- Water (often salt water) collects and rapidly evaporates
- Cycle continues salt and mud and sand accumulate (if still some water left at all times then a salt lake, if not then a Playa)
How do Inselbergs form?
- Harder Rock intrusion in plain of softer rock
- over time softer rock weathers and erodes, leaving harder rock sticking out alone
