BYU GEOL 109 EXAM 2026 PREMIUM
REVIEW SET PROVIDING DETAILED
ANSWER KEY
◉Ice layers. Answer: Differential flow velocity creates tensional
stress which causes crevasses. This zone is called the brittle zone
(up to 60m). Below that is the plastic zone.
◉rates of movement. Answer: Know that there is glacial retreat.
Where the zone of accumulation is < zone of ablation. The ice
continues to move downvalley, but the terminus is receding.
◉What makes a smooth surface?. Answer: Ice wedging
◉Plucking. Answer: pulls up loose fragments
◉What abrades surface?. Answer: Ground-up rock
◉Abrasion. Answer: Glacial striations form parallel to the direction
of ice flow. Makes the rocks very smooth and angular
,◉depositional landforms (2). Answer: Till: Unsorted glacial
sediment
stratified drift: Water re-worked glacial sediment (fine lines)
◉lateral and medial moraines. Answer: Run along the sides of
mountains before they converge into a medial moraine (Y) shape.
◉terminal moraine. Answer: the end of the line moraine, often times
piled up
◉recessional moraines. Answer: indicate periods of stability
◉glacial loess. Answer: When wind deposits "rock flour"
◉Drumlins. Answer: Symmetrical, cone shaped mound formed by
glacial ice. Inside we would find unsorted glacial debris. A perfect
example is the Hill Cumorah
◉Esker. Answer: Snake-like underground rivers under glaciers
◉Cirques. Answer: bowl-shaped rock valley on the side of a
mountain, often with a glacier or permanent snowfield in it.
, ◉Arete. Answer: A sharp crested ridge bounded by 2 cirques (^).
Mountain crests.
◉Horn. Answer: A sharp peak bounded by 3 or more cirques. Top of
the mountain.
◉Hanging valleys. Answer: characteristic U shape valley of a smaller
glacier. Sudden drop off into U-shape valley where glaciers used to
be
◉Who is the father of Glacial Geology?. Answer: Louis Agassiz
◉Pleistocene Epoch. Answer: Global event that disrupted the
hydrologic cycle that began 2-3 mya to 15-20k ya.
--4 major periods of glaciation
-- >100 m drop in sea level
◉Evidence for ice ages [IPCD]. Answer: 1. Isotatic rebound (ice
sheets caused depression of lithosphere)
2. Pluvial lakes in W. U.S. (bonneville) - shorelines and salt flats
3. Channeled Scablands - ice age floods decimated and eroded the
land
REVIEW SET PROVIDING DETAILED
ANSWER KEY
◉Ice layers. Answer: Differential flow velocity creates tensional
stress which causes crevasses. This zone is called the brittle zone
(up to 60m). Below that is the plastic zone.
◉rates of movement. Answer: Know that there is glacial retreat.
Where the zone of accumulation is < zone of ablation. The ice
continues to move downvalley, but the terminus is receding.
◉What makes a smooth surface?. Answer: Ice wedging
◉Plucking. Answer: pulls up loose fragments
◉What abrades surface?. Answer: Ground-up rock
◉Abrasion. Answer: Glacial striations form parallel to the direction
of ice flow. Makes the rocks very smooth and angular
,◉depositional landforms (2). Answer: Till: Unsorted glacial
sediment
stratified drift: Water re-worked glacial sediment (fine lines)
◉lateral and medial moraines. Answer: Run along the sides of
mountains before they converge into a medial moraine (Y) shape.
◉terminal moraine. Answer: the end of the line moraine, often times
piled up
◉recessional moraines. Answer: indicate periods of stability
◉glacial loess. Answer: When wind deposits "rock flour"
◉Drumlins. Answer: Symmetrical, cone shaped mound formed by
glacial ice. Inside we would find unsorted glacial debris. A perfect
example is the Hill Cumorah
◉Esker. Answer: Snake-like underground rivers under glaciers
◉Cirques. Answer: bowl-shaped rock valley on the side of a
mountain, often with a glacier or permanent snowfield in it.
, ◉Arete. Answer: A sharp crested ridge bounded by 2 cirques (^).
Mountain crests.
◉Horn. Answer: A sharp peak bounded by 3 or more cirques. Top of
the mountain.
◉Hanging valleys. Answer: characteristic U shape valley of a smaller
glacier. Sudden drop off into U-shape valley where glaciers used to
be
◉Who is the father of Glacial Geology?. Answer: Louis Agassiz
◉Pleistocene Epoch. Answer: Global event that disrupted the
hydrologic cycle that began 2-3 mya to 15-20k ya.
--4 major periods of glaciation
-- >100 m drop in sea level
◉Evidence for ice ages [IPCD]. Answer: 1. Isotatic rebound (ice
sheets caused depression of lithosphere)
2. Pluvial lakes in W. U.S. (bonneville) - shorelines and salt flats
3. Channeled Scablands - ice age floods decimated and eroded the
land
