Desert Landforms The following questions are based on Figures 4 and 5, a stereog
ID: 295119 • Letter: D
Question
Desert Landforms The following questions are based on Figures 4 and 5, a stereogram, topographic map and color aerial imagery of the Stovepipe Wells region of Death Valley, California. North is to the left side of the stereogram and map. What are the braided markings on the faces of the fans? (Hint: Think about how alluvial fans form.) 1. Look at the upper portions and margins of the alluvial fans shown on the map and in the stereogram (especially the alluvial fan at the mouth of "Grotto Canyon"). In recent years does it appear that erosion or deposition has been more prominent at the tops of these fans? (Hint: Look carefully for evidence of either recent deposition or recent downcutting at the tops of the fans. For example, gullies cut into the tops of the fans are evidence of erosion; the presence or absence of desert varnish can also provide clues as to the location of recent activity on the fans.) 2. (a) (b) Describe the evidence for this that you see in the photographs or map. 3. Suggest a reason and explain why the alluvial fans here vary so greatly in size. Locate the large triangle-shaped hill in the bajada, about 3 inches (8 cm) down from the top of the stereogram. Does it appear that alluvium brought down from the mountains is building up and flowing around this hill? 4. (a) (b) How can you tell? 236Explanation / Answer
1. The alluvial fan near stovepipe wells in Death Valley CA is 9.5 km wide, in order to test the idea of alluvial fan is its scale. The alluvial fans are formed when a water and sediments Pass through a narrow gap between Hills, mountains or Canyon walls and then slows down and spread out when reaches an open plain.
2. a. Yes in the recent years it appears that erosion or deposition has been more prominent at the tops of the fan.
b. Evidence for erosion at the tops of the fan are the gullies that cut into the tops of the fan are the evidence of the erosion.
3. The alluvial fans vary greatly in size because of the varying amount of the sediment flowing into and onto them.
4. a. Yes, the alluvial brought down from the mountains in Bajada is building up and flowing around the hill.
b. The Bajada is the blending of many alluvial fans that are formed in dry climates and can be narrow and flow of two or three streams of water where the dozens of alluvial fans convege. Bajada are found in desert and flash floods which was alluvium down the nearby Hills.