GEOL107 Lecture Notes - Lecture 13: Terminal Moraine, Antarctic Bottom Water, Absolute Time And Space
9 Oct 2018
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Document Summary
When glacial ice stops advancing, deposits rock material that was transported. All sediment of glacial origin found anywhere on land or seafloor. Drift deposit from melting of ice, heterogeneous mixture of particle sizes, not layered by grain size; mix. Drift deposits from meltwater flowing away from glaciers, layered by grain size (big on bottom, small on top) Till along the side of a glacial valley. Formed where two glacial valleys are joined. Till deposit where glacier stopped and began to melt. End moraine that marks furthest position of glacial advance. Deposited by glacial meltwater flowing beneath ice. Created by isolated block of ice that melts after main glacier has retreated. Cyclical layers of sediment deposited on seasonal basis (2 per year) in glacial lakes. Silt and fine sand deposited late spring and summer from sediment load from meltwater. Clay deposited from suspended load during winter months when meltwater is reduced and lake surface freezes.
