eesci final 3

-most recent ice ages

-persistant mass of ice that forms on land and flows like water (ductile deformation at depth-brittle fracturing near surface) down slope under the influence of gravity

• terrestrial - erosion (horns cirques and u shaped valleys) glacial striations-scratches in bedrock
• depositional environments- ground moraine under ice
• moraine ridge- at the edge of glacier
• outwash plain - sediments worked by streams
• eratics - boulders in the middle of nowhere

• O18 and O16 ratios measured in fossil foraminifera
• Core evidence - annual bands of ice give a climate record, ox. isotopes can give you temp.

• Isostatic effects- vertical movement of lithosphere & asthenosphere (uplift)
• Drainage effects - creation of Great Lakes, great basin -fluvial lakes and ice dams
• Sea level falls when glaciers form, rises when they melt

• extinction of large mammale in North America
• climate change-( but extinction did not happen all at once worldwide)
• Overhunting - a small population of large mammals (inverse correlation with body size) worldwide timing matched human development