Glacial Events in the Transantarctic Mountains: A Record of the East Antarctic Ice Sheet

  1. Mort D. Turner and
  2. John E. Splettstoesser
  1. Paul A. Mayewski2 and
  2. Richard P. Goldthwait3

Published Online: 16 MAR 2013

DOI: 10.1029/AR036p0275

Geology of the Central Transantarctic Mountains

Geology of the Central Transantarctic Mountains

How to Cite

Mayewski, P. A. and Goldthwait, R. P. (1986) Glacial Events in the Transantarctic Mountains: A Record of the East Antarctic Ice Sheet, in Geology of the Central Transantarctic Mountains (eds M. D. Turner and J. E. Splettstoesser), American Geophysical Union, Washington, D. C.. doi: 10.1029/AR036p0275

Author Information

  1. 2

    Institute of Polar Studies and Department of Geology and Mineralogy, the Ohio State University, Columbus, Ohio 43210

  2. 3

    Institute of Polar Studies and Department of Geology and Mineralogy, the Ohio State University, Columbus, Ohio 43210

Publication History

  1. Published Online: 16 MAR 2013
  2. Published Print: 1 JAN 1986

ISBN Information

Print ISBN: 9780875901848

Online ISBN: 9781118664797

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Keywords:

  • Bedrock geology;
  • Clay minerals;
  • Isostasy and eustasy;
  • Lithology and mineralogy;
  • Moraines and tectonism;
  • Morphology;
  • Shackleton Glacier;
  • Sirius formation

Summary

The Transantarctic Mountains form a mountainous division between East and West Antarctica extending 2900 km from the Pensacola Mountains to northern Victoria Land. The mountains constrict the flow of East Antarctic ice, creating outlet glaciers which form a connection between the inland ice sheet and the Ross Ice Shelf. Glacial deposits recording former ice surface levels of outlet glaciers can therefore be used to interpret East Antarctic ice sheet and Ross Ice Shelf fluctuations. A glacial history is formulated based upon the investigation and comparison of two areas: (1) the Queen Maud Mountains, a 450-km stretch from Scott Glacier to Beardmore Glacier and (2) southern Victoria Land, a 150-m stretch from Taylor Valley to Fry Glacier. Four glacial events are recognized, differentiated, and correlated with datable deposits in the Transantarctic Mountains. The oldest and most extensive, Queen Maud Glaciation (>4.2 m.y. B.P.), crops out as a lodgment till overlain by ice contact deposits and is discussed in terms of its (1) extent and dimensions, (2) basal contact, (3) structure, (4) particle size distribution, (5) lithology, mineralogy, and organic components, (6) rounding and freshness of grains, and (7) directional indicators. Features such as meltwater channels and potholes record a marked climate amelioration, Gallup Interglacial (>2.7 to <4.2 m.y. B.P.), following the Queen Maud Glaciationu Lateral moraines record the latest glacial events, Scott Glaciation (>2.1 to <2.7 m.y. B.P.), Shackleton Glaciation (>0.049 to <1.6 m.y. B.P.), and Amundsen Glaciation (<9490 years B.P.). These lateral moraines are described and correlated by investigation of (1) elevation and continuity relative to present ice surface, (2) morphology, thickness of drift, and presence of an ice core, (3) weathering of surficial clasts, and (4) soils composing these moraines in terms of particle size distribution, salt content, pH, and clay minerals. The general implications derived from the resultant glacial history and ice surface reconstructions suggest the following conclusions: (1) The western portions of the East Antarctic ice sheet have fluctuated synchronously throughout the late Cenozoic. Only four maxima have been recorded since the middle of the Pliocene. The extensive areal coverage of these glacial events points to a broad-scale cause. (2) A crude morphology of the Antarctic ice sheet can be determined for the four glacial maxima. This morphologic description includes information concerning the movement of the main ice dome, the surface elevation of the ice sheet, the relative proportion of ice-free areas, the grounding line surrounding the ice sheet, and the volume of the ice sheet. (3) A “super” Antarctic ice sheet, which has notsince been equaled in size, covered the Antarctic continent at a time more than 4.2 m.y. ago. (4) Changes in the size of the Antarctic ice sheet have a marked effect on world-wide sea level and climate.