Sub-Ice Relief and Geology of East Antarctica

• Main Author: Drewry, David J
• Format: Doctoral or Postdoctoral Thesis
• Language: English
• Published: Scott Polar Research Institute 1973
• Subjects: Antarctic; East Antarctica; Transantarctic Mountains; Antarc*; Antarctica; Ice Sheet; Scott Polar Research Institute
• Online Access: https://doi.org/10.17863/CAM.14164; https://www.repository.cam.ac.uk/handle/1810/268052

Continuous airborne radio echo sounding by the Scott Polar Research Institute has enabled delimitation of the sub-ice topographic configuration of Eastern Antarctica. Reduction and evaluation of profiles of ice/bedrock interface, combined with critically assessed results of previous geophysical and geological investigations, has allowed some interpretation of the geological structure and glacial history of East Antarctica. A comparison of the relative and absolute accuracy of radio echo sounding results and seismic-gravity data in East Antarctica indicates an average agreement between the different techniques to better than 10%. The results of some previously unchecked traverses, however, have been revised. Maps and profiles of bedrock relief have been compiled and are discussed in general. They have provided the basis for a quantitative investigation and regionalization of sub-ice relief based upon the statistical variation of the vertical and horizontal components of surface roughness. The resulting. topographic regions along with details of radio echo profiles and other geophysical measurements have enabled interpretation of aspects of Antarctic crustal structure including: 1) estimates of the isostatically compensated bedrock surface 2) estimates of crustal thickness 3) the nature of the transition between the fault-block Transantarctic Mountains and the East Antarctic craton. 4) the extent of the topographically distinctive Beacon Supergroup lithological province 5) the delimitation of the major neotectonic characteristics of East Antarctica - zones of uplift and depression 6) a generalized outline of the major tectonic units of East Antarctica. Investigations of glacial geological history have been assisted by detailed mapping and analysis of sub-ice relief adjacent to the Transantarctic Mountains. Evidence of inland-trending valleys of probable glacial origin suggests that glaciers once descended both flanks of the Mountains during a local, upland glacial phase predating the continental ice sheet. Such ...