Crustal structure of the Filchner‐Ronne Shelf and Coats Land, Antarctica, from gravity and magnetic data: Implications for the breakup of Gondwana

New geophysical compilations link crustal block motion to Jurassic extension and strike-slip faulting in the Weddell Sea Rift System of West Antarctica

“…6) which broadly agree with those previously recognised and interpreted e.g. (Golynsky and Aleshkova, 1997b;Mieth and Jokat, 2014;Studinger and Miller, 1999). …”

“…Modelling indicates 5-10 km of sedimentary infill within the rift system, overlying ~20 km continental crust (Studinger and Miller, 1999). This supports the suggestion that a preexisting continental "Filchner Block" should be included in tectonic reconstructions of the WSRS and models of HEW movement (Studinger and Miller, 1999).…”

“…7 of the region (Aleshkova et al, 1997;Ferris et al, 2000;Golynsky and Aleshkova, 1997b;Hübscher et al, 1996;King and Bell, 1996;Leitchenkov and Kudryavtzev, 1997;Studinger and Miller, 1999). These studies, although in general agreement that the WSRS reflects a broad continental rift, did not clearly recognise major faults or identify large-scale mechanisms that could have enabled crustal block movements or rotations compatible with those required by conventional far travelled tectonic models.…”

“…These datasets are interpreted, together with limited existing seismic data, satellite magnetic data, and with reference to the geological literature, to re-investigate the crustal architecture of the WSRS and to reassess its tectonic and kinematic evolution with respect to the early phases of Gondwana breakup. Our new integrated interpretation of the crustal architecture of the WSRS indicates the southern WSRS is a highly extended terrane, with voluminous rift-related Jurassic magmatism, as suggested by some previous authors (Dalziel et al, 2000;Studinger and Miller, 1999). We discuss a range of tectonic scenarios for WSRS evolution based on our geophysical interpretations.…”

“…Across the WSRS, gravity data support the presence of thinned continental rather than oceanic crust (Aleshkova et al, 1997;Block et al, 2009;Studinger and Miller, 1999). Modelling indicates 5-10 km of sedimentary infill within the rift system, overlying ~20 km continental crust (Studinger and Miller, 1999).…”