LATE PALEOZOIC GLACIATION IN ANTARCTICA: ARE MODELS DEPICTING AN IMMENSE ICE SHEET CORRECT?
Reexamination of the glacigenic units in southern Victoria Land, the Darwin Mountains, and the central Transantarctic Mountains reveals that glacilacustrine or glacimarine sediments were deposited within basins, and that subglacial diamictites were deposited only locally along basin margins. Ice free areas were also common. Re-correlation of fossil spores and pollen with Australian palynomorph zones indicate that the Antarctic glacigenic strata are restricted to the Lower Permian. These findings indicate that glaciation was less widespread (temporally and spatially) than previously hypothesized. It is also unlikely that a single ice sheet covered Antarctica throughout the Carboniferous and Permian. Instead, available data are better explained by a short-lived Early Permian glacial interval consisting of multiple ice sheets, or perhaps even consisting of ice caps and alpine glaciers.
Thick glacigenic deposits that are widespread throughout the mountain ranges in Antarctica (e.g., Pensacola Mtns, Ellsworth Mtns, Wisconsin, Range, Scott and Amundsen Glacier areas and northern Victoria Land) have not been examined in the field in the last 25 to 40 years. Significant advances in linking glacial deposits to glacial and glacimarine processes have been made during this time. Reexamination of the glacigenic deposits in these areas may lead to new models of late Paleozoic glacial history, a history that recent studies have begun to clarify.