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The evolution of West (Lesser) Antarctica and its relation to East (Greater) Antarctica have major implications for global plate interactions, paleoclimate, and paleobiogeography, as well as Gondwanaland reconstruction. Analyses of marine geophysical data still lead to seemingly unacceptable overlap between the Antarctic Peninsula and the South American continent or else to geologically questionable relationships. A review of the relevant geological and geophysical data indicates that the problem lies in microplate movement and crustal thinning within West Antarctica during Gondwanaland breakup in the late Mesozoic and Cenozoic. The available data allow a range of possible reconstructions with West Antarctica subdivided into several discrete or semidiscrete microplates. Final solution of this problem requires additional geological and, particularly, geophysical data from West Antarctica as a whole, and the Weddell Sea‐Ross Sea embayment in particular. Meantime, it seems inadvisable to use the present continental outline of Antarctica on the Pacific side of the Transantarctic Mountains in reconstructing Gondwanaland.

Are there petroleum resources in Antarctica?, by John C. Behrendt. in pre-break-up Triassic strata, to intracontinental rocks of the Beacon Supergroup and Ferrar. Group. These flat-lying rocks are especially wide-in the Beardmore Glacier area locality 69, fig. in the Devonian through Jurassic Beacon Super-. PaleoTerra: Devonian Lithological Database: Sources A-G basin antarctica terra: Topics by E-print Network-OSTI The Beacon Supergroup Devonian-Triassic and. Ferrar Group Jurassic in the Beardmore Glacier area, Antarctica. Ant. Res. Ser., 36:339-428. Barrett, P.J. Summary: Shetland Islands and perhaps the Antarctica Peninsula region. Pole in December 1986 by the Radio Physics Research group at Bell Laboratories. Petroleum and Mineral Resources of Antarctica Antarctic Region. sequence of g~erally flat-lying rocks, the Beacon Supergroup, which are composed of shallow marine-non-marine quartzose sediments of Devonian age raylor Group, unconformably overlain by Collinson, J.W. & Isbell, lL., 1986-Permian-Triassic sedimentology of the Beardmore Glacier region. These rocks record ordovician Sm-Nd ages, Devonian Rb-Sr ages, and. 25 Figure 3.1 Mafic schist belonging to the Northern Group on west shore of Brents mouw Peak in the Beardmore Glacier region of Antarctica in conjunction with in the

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In the central Transantarctic Mountains region, siliciclastic strata of the Permian-Triassic Victoria Group (Beacon Supergroup), the Gondwana sequence in Antarctica, have both cratonic and magmatic arc provenance. Volcaniclastic strata occur in the upper part of the Permian Buckley Formation, whereas the Triassic Fremouw and Falla formations are more quartzose. Two sandstones in the upper Buckley and one near the base of the Fremouw, and immediately above the Permo-Triassic boundary, in the Shackleton Glacier region have yielded detrital zircon U/Pb SHRIMP age populations with clear evidence for a contemporaneous source. The stratigraphically lowest sample, about 70 m below the top of the Buckley Formation, is dominated by zoned igneous zircons of late Permian age. The sample from near the top of the Buckley Formation, about 40 m below the Permo-Triassic boundary, predominantly has zoned igneous zircons with the principal age peak again late Permian but with subordinate Devonian and Cambrian age peaks. The third sandstone from just above the Permo-Triassic boundary yielded zircons mainly of Neoproterozoic to Cambrian age. These results indicate a Permian-Triassic magmatic source existed during upper Buckley time, which is consistent with paleocurrent indicators of flow from the West Antarctic flank of the Permian-Triassic foreland basin, the inferred plate margin (Panthalassan) flank. The Devonian source is attributed to the Ford granodiorite suite in Marie Byrd Land, West Antarctica. Because Beacon strata cover the Cambrian Ross orogen and extend onto older basement, the Cambrian and Upper Proterozoic zircons are interpreted to be reworked from sandstones (Ordovician, Devonian, Early Permian in age) exposed in the Permian-Triassic Gondwanide orogen as a result of uplift of a fold and thrust belt by late Permian time.