HR: 16:00h
AN: V14C-01    [Abstracts]
TI: The Transantarctic Mountains between South Pole and Scott Glacier area: a geophysical perspective
AU: * Studinger, M
EM: mstuding@ldeo.columbia.edu
AF: Lamont-Doherty Earth Observatory, 61 Route 9W, Palisades, NY 10964 United States
AU: Bell, R E
EM: robinb@ldeo.columbia.ed
AF: Lamont-Doherty Earth Observatory, 61 Route 9W, Palisades, NY 10964 United States
AU: Buck, W
EM: buck@ldeo.columbia.edu
AF: Lamont-Doherty Earth Observatory, 61 Route 9W, Palisades, NY 10964 United States
AB: The Transantarctic Mountains and associated West Antarctic rift system are among the most enigmatic tectonic regions on Earth and many aspects of their formation remain controversial or little understood. The difficulty to resolve the controversies is mainly related to a gap in the onland geologic record of the uplift and exhumation history between the extrusion of the Jurassic Kirkpatrik Basalts (~180 Ma) and the Eocene glacial sediments (~34 Ma) in the Ross Embayment. Furthermore, the geologic footprint of the mountains inland of the Transantarctic Mountains has not yet been sampled because of the ice cover and geophysical data coverage is sparse. In order to better constrain the tectonic and geologic framework aerogeophysical remote sensing of the hinterland is a crucial step forward. The aerogeophysical data set presented here is part of a project to study variations in crustal architecture along the Transantarctic Mountains along two aerogeophysical transects. The aeromagnetic anomaly field is generally very smooth. Over the Transantarctic Mountains, the anomaly field shows several small (tens of kilometers) positive amplitudes that can be correlated with known rock outcrops of Granite Harbour Intrusives. Source depth estimates, using multiple-source Werner deconvolution, indicate shallow sources for the Granite Habour Intrusives. The typical pattern of short-wavelength and high amplitude anomalies caused by the Jurassic Ferrar doleritic dykes and sills along the TAM is absent. A comparision with an aeromagnetic transect in Southern Victoria Land shows that there are no or little Ferrar rocks in the Scott Glacier area. We have also mapped several geologic contacts, often fault related, by multiple-source Werner deconvolution of the magnetic data. We used gravity data to constrain the crustal thickness variations along a transect parallel to 150 °W.
DE: 1517 Magnetic anomalies: modeling and interpretation
DE: 3010 Gravity and isostasy (1218, 1222)
DE: 8122 Dynamics: gravity and tectonics
DE: 9310 Antarctica (4207)
SC: Volcanology, Geochemistry, Petrology [V]
MN: Fall Meeting 2005