Geomorphology and Quaternary Geology Flashcards
7 cards from real ASBOG practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Geomorphology and Quaternary Geology flashcards as text
Solifluction is a periglacial mass-wasting process that occurs when:
Answer: Frozen ground thaws and saturated soil slowly flows downslope
Solifluction occurs when the active layer above permafrost thaws and becomes saturated, causing slow downslope flow of waterlogged soil.
Which of the following best describes a braided stream?
Answer: Multiple interconnected channels separated by mid-channel bars
Braided streams have multiple shifting channels divided by transient bars of coarse sediment, typically reflecting high sediment load and variable discharge.
Tafoni are weathering features consisting of cavernous hollows in rock surfaces, formed primarily by:
Answer: Salt crystallization and differential chemical weathering
Tafoni form through salt weathering and differential chemical weathering, creating honeycomb or cavernous textures on rock surfaces.
What is the primary mechanism that forms oxbow lakes?
Answer: Cutoff of a meander loop as a river straightens its course
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.
Which Quaternary stratigraphic boundary is formally defined at the Global Boundary Stratotype Section and Point (GSSP) in the Vrica section in Italy?
Answer: Pliocene-Pleistocene boundary at ~2.58 Ma
The base of the Quaternary (Pleistocene) is formally defined at 2.58 Ma at the Vrica GSSP in Italy, marked by a paleomagnetic reversal.
Desert pavement is a surface layer of tightly packed stones that forms through:
Answer: Deflation removing fine particles and concentrating coarse clasts at the surface
Desert pavement forms primarily by deflation, where wind removes fine-grained material, leaving a lag of coarser clasts that armor the surface against further erosion.
A striated boulder transported far from its source rock type is called an:
Answer: Erratic
A glacial erratic is a boulder transported by ice and deposited far from its bedrock source, often identifiable because it differs in rock type from local bedrock.