the sea fills the lower endlandforms produced by ice caps and ice sheets:* abrasional features-glacial striations/grooves- parallel scratches and grooves in bedrock, aligned in the direction of flow-glacial polish- sand and silt polish bedrock* streamlined features-drumlin- streamlined hill of glacial sediments-rock drumlin- streamlined hill made of bedrockGlacial Deposits (glacial drift-from glaciers and streams they produce)-sediments deposited by a glacier or by streams produced by melting glacier ice-carried sediments are neither sorted nor stratified-load concentrated at base and sides, sand and silt (rock flour) (pluck/abrade)ice-laid deposits* till- nonsorted drift deposited directly from ice* erratic- glacially deposited rock that is different from the underlying bedrock* glacialmarine drift- sediment deposited on the sea floor from ice shelves or bergs (till in water) (dropstones)* moraines- accumulation of drift unrelated to underlying bedrock-ground moraine- widespread gentle undulating knolls-lateral morraine- ridge along side of valley-medial moraine- ridge along glacier center-terminal (end) moraine- ridge along terminusstratified drift* outwash- stratified sediment deposited by glacial streams-outwash plain- if streams freely swing back and forth-valley train- meltwater streams confined by valley walls-outwash terraces- during retreat, sediment load reduced, stream cuts into outwash deposits* ice-contact stratified drift- sediment deposites into drifts which slump following recession-kame- small hill-kettle- small basin-esker- long, sinuous ridge of sand and gravelThe Glacial Ages-periods of geologic time when glaciers coered extensive regions of the earthclimate change over time* climate is cooling over tens of millions of years-now at point of maximum warmth* last 3 million years- glacial-interglacial cycles (*20)glacial age changes1.number of glaciers increase2.volume of glaciers increase* during the last glacial age (...
