Tuesday, 28 August 2007
2.PS-61
Drake Passage and Bransfield Strait – new geophysical data and modeling of the crustal structure
Sergey P. Levashov1, Mykola A. Yakymchuk1, Ignat N. Korchagin2, V.G. Bachmutov2, V.D. Solovyov2, and D.N. Bozhezha3. (1) Institute of the applied problems of Ecology, Geophysics and Geochemistry, 1, Laboratorny lane., Kiev, 01133, Ukraine, (2) Institute of Geophysics of National Academy of Science of Ukraine, Kiev, Ukraine, (3) Management and Marketing Center of Institute of Geological Science of NAS Ukraine, Kiev, Ukraine
The 2004 and 2006 Ukrainian Antarctic programs acquired new geoelectrical data (“short-impulse electromagnetic field formation" – FSPEF, and "vertical electric-resonance sounding" – VERS) along profiles across Drake Passage and along Bransfield Strait, Antarctic Peninsula, with the aim of studying the crustal structure of these features down to depths of >30 km. Beneath the Drake Passage, Moho is interpreted at extremely shallow depths of 8–12 km; the origin of a deeper anomalous layer at 15–20 km is unknown at this stage. Both Moho and the deeper layer show strong relief in the vicinity of the Shackleton Fracture Zone. Moho in the Bransfield Strait profile is interpreted at depths of 12–28 km, while the lower crustal layers and crust–mantle transition zone show radical variations in depth and thickness. These variations likely reflect the complex geological history and the current tectonic setting as an incipient oceanic back-arc basin.