ASBOG Geomorphology and Quaternary Geology 5

Question 1

Solifluction is a periglacial mass-wasting process that occurs when:

Accepted Answer

Frozen ground thaws and saturated soil slowly flows downslope

Answer

Solifluction occurs when the active layer above permafrost thaws and becomes saturated, causing slow downslope flow of waterlogged soil.

Question 2

Which of the following best describes a braided stream?

Accepted Answer

Multiple interconnected channels separated by mid-channel bars

Answer

Braided streams have multiple shifting channels divided by transient bars of coarse sediment, typically reflecting high sediment load and variable discharge.

Question 3

Tafoni are weathering features consisting of cavernous hollows in rock surfaces, formed primarily by:

Accepted Answer

Salt crystallization and differential chemical weathering

Answer

Tafoni form through salt weathering and differential chemical weathering, creating honeycomb or cavernous textures on rock surfaces.

Question 4

What is the primary mechanism that forms oxbow lakes?

Accepted Answer

Cutoff of a meander loop as a river straightens its course

Answer

Oxbow lakes form when a river cuts through a meander neck during a flood, abandoning the old loop which becomes isolated as a crescent-shaped lake.

Question 5

Which Quaternary stratigraphic boundary is formally defined at the Global Boundary Stratotype Section and Point (GSSP) in the Vrica section in Italy?

Accepted Answer

Pliocene-Pleistocene boundary at ~2.58 Ma

Answer

The base of the Quaternary (Pleistocene) is formally defined at 2.58 Ma at the Vrica GSSP in Italy, marked by a paleomagnetic reversal.

ASBOG - Association of State Boards of Geology Practice Test

ASBOG - Association of State Boards of Geology Practice Test

ASBOG Geomorphology and Quaternary Geology 5