Desert Landscapes and Erosion Concepts

The lecture by Tor Lacy covers the distribution, weathering, erosion, and landforms of deserts, focusing on the southwestern part of North America. It explains the geographic and atmospheric conditions that lead to desert formation, the role of wind and water in shaping desert landscapes, and the evolution of these landscapes over time. Key landforms such as alluvial fans, playas, and sand dunes are discussed, along with the geological processes that create them.

Which factor is primarily responsible for the distribution of warm deserts near the equator?

• High rainfall

• High altitude

• Low angle of incidence of the sun's energy

• Proximity to oceans

What is the main reason for the formation of deserts in the rain shadow of mountains?

• High temperatures

• High wind speeds

• Proximity to the equator

• Descending dry air

What is the primary agent of erosion in desert landscapes?

• Volcanoes

• Wind

• Glaciers

• Streams

What are alluvial fans primarily composed of?

• Volcanic ash

• Sediment deposited by streams

• Wind-blown sand

• Glacial till

What is a bajada?

• A merged alluvial fan

• A steep mountain slope

• A dry lake bed

• A type of sand dune

What is the characteristic feature of a cuesta?

• A sand dune

• A flat valley floor

• A steep and a less steep side

• A dry lake bed

What causes sand dunes to move?

• Tectonic activity

• Rainfall

• Wind

• Earthquakes

What is the Great Basin Desert known for?

• Dense vegetation

• Intense crustal extension

• Volcanic activity

• High rainfall

What are inselbergs?

• Dry lake beds

• Isolated rock islands

• Sand dunes

• Alluvial fans

What is the final stage in the evolution of a desert landscape?

• Formation of alluvial fans

• Development of bajadas

• Erosion to form pediments

• Formation of sand dunes