Geomorphology and Quaternary Geology Flashcards

Which landform is produced when a river deposits sediment at its mouth as it enters a standing body of water?

Answer: Delta

A delta forms when a river loses velocity and deposits sediment as it enters a lake or ocean.

The Wisconsin glaciation in North America ended approximately how many years ago?

Answer: 10,000 years ago

The Wisconsin glacial stage ended approximately 10,000 years before present, marking the start of the Holocene.

A 'roche moutonnée' is a glacially sculpted bedrock feature characterized by:

Answer: Smooth upstream face and steep downstream face

Roche moutonnée has a smooth, striated stoss (upstream) side shaped by abrasion and a rough, steep lee (downstream) side from glacial plucking.

What term describes the maximum elevation above which snow accumulation exceeds ablation on a glacier?

Answer: Equilibrium line altitude

The equilibrium line altitude (ELA) separates the accumulation zone above from the ablation zone below on a glacier.

Which Quaternary dating method relies on the accumulation of cosmogenic nuclides in surface rocks exposed to cosmic radiation?

Answer: Surface exposure dating

Surface exposure dating measures cosmogenic nuclides like ¹⁰Be and ²⁶Al that accumulate in rock surfaces exposed to cosmic rays.

A pediment is best described as:

Answer: A gently sloping erosional bedrock surface at a mountain front

A pediment is a low-angle erosional surface cut into bedrock at the base of a mountain range, often veneered with thin alluvium.

Which term refers to wind-deposited silt that forms thick, widespread blankets of sediment?

Answer: Loess

Loess is aeolian silt transported and deposited by wind, forming extensive blankets across many mid-latitude regions.