Basement interpretations from airborne magnetic and gravity dataover the Lambert Rift region of East Antarctica

摘要

Geological exposures in the Lambert Rift region of East Antarctica comprise scatteredcoastal outcrops and inland nunataks sporadically protruding through the Antarctic icesheet from Prydz Bay to the southernmost end of the Prince Charles Mountains. Thisstudy utilized airborne magnetic, gravity, and ice radar data to interpret the distribution andarchitecture of tectonic terranes that are largely buried beneath the thick ice sheet. Free-airand Bouguer gravity data are highly influenced by the subice and mantle topography,respectively. Gravity stripping facilitated the removal of the effect of ice and Moho, andthe residual gravity data set thus obtained for the intermediate crustal level allowed adirect comparison with magnetic data. Interpretation of geophysical data also providedinsight into the distribution and geometry of four tectonic blocks: namely, the Vestfold,Beaver, Mawson, and Gamburtsev domains. These tectonic domains are supported bysurface observations such as rock descriptions, isotopic data sets, and structural mapping.