UTIG Special Seminar: Tom Jordan, British Antarctic Survey
||December 9, 2016 at 10:30 am
||December 9, 2016 at 11:30 am|
| ||Location:||PRC ROC Room 1.603|
| ||Contact:||Ian Dalziel, email@example.com, 512-471-0431|
| ||URL:||Event Link|
Mapping the hidden mosaic of Antarctica; From microplate movement to continental assembly
Due to the blanketing ice sheet and remote location Antarctic is one of the least explored and poorly understood regions on our planet. The key geological division of Antarctica is between an ancient East Antarctica craton, once at the heart of the Gondwanan supercontinent, and the collage of fragments making up the tectonically more active West Antarctic province. Within West Antarctica geological studies suggest that as a pre-cursor to the breakup of Gondwana one of these fragments, the Haag Ellsworth Whitmore Mountains block, was translated 1500 km and rotated through 90° from a position between East Antarctica and South Africa. Geophysical data has been used to challenge this notion, and suggest little or no block motion. Here we use new regional compilations and analysis of magnetic and gravity data to discuss the feasibility and implications of an alternative tectonic model with significant (500 km) movement, but limited (30°) block rotation. In contrast to West Antarctica the East Antarctic craton has been seen as a monolithic block, split by simple linear geological boundaries extrapolated from sparse coastal outcrops. However, the most up to date geophysical data from the PolarGAP survey around the South Pole supports an alternative view that East Antarctica is also a composite structure, with a complex of sutures and boundaries resulting from continental assembly, which continue to influence the sub-ice topography to this day.