Glacial Sedimentation: Introduction

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Glacial Sedimentation Introduction complex,
poorly studied form of sedimentation many
different environments, comparable to studying
all marine and coastal environments at
once most studies are of ancient glacial
deposits the fact that many of us here study
modern glacial sedimentation is somewhat
unusual this limitation affects
the understanding of the ancient deposits
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Glacial Periods in Earths History See figure
8.1 Huronian Glaciation 2,700-2,300
Ma Centered over eastern Canada (Gowganda
Glaciation) Glacial-marine deposits in South
Africa and western Australia Late Precambrian
Glaciation most widespread continental
glaciation every continent except
Antarctica mainly glacial marine deposits
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Early Paleozoic Glaciation Ordovician through
Silurian Saharan Ice Sheet centered over
central Africa comparable in size to the
current Antarctic Ice Sheet many of the
deposits remain poorly studied, are either
glacial or glacial-marine Late Paleozoic
Glaciation covered much of Gondwana thickest
deposits in eastern South America and West
Antarctica
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Late Cenozoic Glaciation began in
Antarctica, at least as early as Late Oligocene
(by this time glaciers existed at the
coast) by Pliocene, ice sheets developed in
Northern Hemisphere many glacial-interglacial
cycles since Pliocene Why since
Pliocene? glacial sedimentation still
dominates at high latitudes
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(Composite isotope curve from Abreu and
Anderson, 1999Cycle Chart from Hardenbol et
al, 2000and eustatic curve from Haq et al.
1987 andMitchum et al., 1994)
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DSDP/ODPDRILL SITES
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Subglacial Topography of Antarctic (from Denton
et al., 1991)
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Ice Sheet Drainage
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The Antarctic Ice Sheets

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Ice Sheet Reconstructions (Anderson et al., 2002)
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Retreat History

• EAIS vs WAIS
• (Anderson et al., 2002)

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Recent Changes and Their Implications
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