ASBOG Geomorphology and Quaternary Geology 3

Question 1

Stream terraces form primarily as a result of:

Accepted Answer

Stream incision following a change in base level or sediment supply

Answer

Stream terraces are abandoned floodplains left elevated when a river incises downward due to falling base level or decreased sediment supply.

Question 2

Which process describes the downslope movement of water-saturated soil and debris as a coherent mass over a curved failure surface?

Accepted Answer

Rotational slump

Answer

A rotational slump involves movement along a concave-upward failure surface, with the mass rotating backward as it slides.

Question 3

Pleistocene pluvial lakes, such as Lake Bonneville, formed primarily because of:

Accepted Answer

Increased precipitation and reduced evaporation under cooler climates

Answer

Pluvial lakes expanded during glacial intervals due to cooler, wetter conditions that reduced evaporation and increased precipitation.

Question 4

What is the term for a crescent-shaped sand dune with horns pointing downwind?

Accepted Answer

Barchan

Answer

Barchan dunes are crescent-shaped with the concave side downwind, forming where sand supply is limited and wind direction is consistent.

Question 5

Drumlins are elongated glacial landforms that indicate:

Accepted Answer

The direction of former glacial flow

Answer

Drumlins are streamlined subglacial landforms whose long axes parallel the direction of ice flow, with the blunt end facing up-ice.

ASBOG - Association of State Boards of Geology Practice Test