Central Transantarctic Mountains, Antarctica
Glacial erosion c. 34 million years ago
The erosional history of Antarctica is central to understanding the long-term interplay between climate, tectonics, and the cryosphere in the high latitudes on million-year timescales. Radiative and astronomical forcing influences the development of ice sheets; ice sheet dynamics control the rate and pattern of glacial erosion and associated isostatic uplift, sculpting bedrock topography; bedrock topography in turn exerts significant control over ice sheet formation and stability. Global climatic transitions and the development of the Antarctic ice sheet have been documented with increasing precision. However, when and the extent to which glaciation impacted the subglacial landscape of Antarctica remains poorly defined. This project involved the acquisition of an extensive new apatite U-Th/He dataset (apatite He) from the central Transantarctic Mountains to address this gap. The Transantarctic Mountains expose an expansive area of bedrock that has the potential of directly yielding information about the effects of glaciation on subglacial erosion. If short-term measurements of glacial sediment yield from modern warm-based glaciers can be extrapolated to geologic timescales, the magnitude of erosion and attendant cooling in Antarctica should be significant enough to be clearly reflected in the low-temperature thermochronologic record.
J. He, S.N. Thomson, P.W.Reiners, S. Hemming, K. Licht. (2021). Rapid erosion of the central Transantarctic Mountains at the Eocene-Oligocene transition: Evidence from skewed (U-Th)/He date distributions near Beardmore Glacier. Earth and Planetary Science Letters. https://doi.org/10.1016/j.epsl.2021.117009
Glacial erosion c. 34 million years ago
The erosional history of Antarctica is central to understanding the long-term interplay between climate, tectonics, and the cryosphere in the high latitudes on million-year timescales. Radiative and astronomical forcing influences the development of ice sheets; ice sheet dynamics control the rate and pattern of glacial erosion and associated isostatic uplift, sculpting bedrock topography; bedrock topography in turn exerts significant control over ice sheet formation and stability. Global climatic transitions and the development of the Antarctic ice sheet have been documented with increasing precision. However, when and the extent to which glaciation impacted the subglacial landscape of Antarctica remains poorly defined. This project involved the acquisition of an extensive new apatite U-Th/He dataset (apatite He) from the central Transantarctic Mountains to address this gap. The Transantarctic Mountains expose an expansive area of bedrock that has the potential of directly yielding information about the effects of glaciation on subglacial erosion. If short-term measurements of glacial sediment yield from modern warm-based glaciers can be extrapolated to geologic timescales, the magnitude of erosion and attendant cooling in Antarctica should be significant enough to be clearly reflected in the low-temperature thermochronologic record.
J. He, S.N. Thomson, P.W.Reiners, S. Hemming, K. Licht. (2021). Rapid erosion of the central Transantarctic Mountains at the Eocene-Oligocene transition: Evidence from skewed (U-Th)/He date distributions near Beardmore Glacier. Earth and Planetary Science Letters. https://doi.org/10.1016/j.epsl.2021.117009