Alluvial Fans and Depositional Environments Quiz

What primarily influences the geometry of an alluvial fan?

• The type of vegetation in the area

• The rate and duration of mountain uplift and climate

• The presence of wildlife

• The color of the soil

Which part of an alluvial fan is located at the very beginning of the fan system?

• Fan toe

• Fan apex

• Mid fan

• Fan head

What is a characteristic feature of debris flow deposits?

• High density and viscosity

• Fine-grained sediment

• Uniform grain size

• Presence of clay

How can you distinguish debris flow deposits from sheet flood deposits?

• By their temperature

• By their grain size distribution

• By their smell

• By their color

What is a common feature of sheet flood deposits?

• Presence of large boulders

• Poor sorting

• Cross bedding and lamination

• High density

What is a key indicator of sieve deposits in the field?

• Uniform grain size

• High density and viscosity

• Excellent sorting and reverse grading

• Presence of large boulders

Which environment is typically adjacent to alluvial fans?

• Rainforest

• Tundra

• Fluvial environments

• Desert

What type of rock is commonly found in alluvial fan strata?

• Basalt

• Limestone

• Conglomerate or breccia

• Shale

What is a characteristic of the stratigraphy of alluvial fans?

• Lack of cross bedding

• Uniform particle size

• Consistent flow direction indicators

• Fine-grained deposits throughout

What happens to grain size as you move down an alluvial fan?

• It becomes coarser

• It remains the same

• It disappears

• It becomes finer