Rb-Sr Geochronology of the Region Between The Antarctic Peninsula and The Transantarctic Mountains: Haag Nunataks and Mesozoic Granitoids

The Gondwana Plate margin in the Weddell Sea sector: Zircon geochronology of Upper Paleozoic (mainly Permian) strata from the Ellsworth Mountains and eastern Ellsworth Land, Antarctica

“…1). The few isolated outcrops of metasedimentary rocks adjacent to the Middle Jurassic granites (Millar and Pankhurst, 1987;Pankhurst et al, 1991;Craddock et al, 2008a) in the Ellsworth structural domain , which is located between the Whitmore Mountains and the Ellsworth Mountains, have a similar NW-SE structural grain. In the accepted orientation of the EWB in Gondwana reconstructions, those NW-SE structures are trending in toward the craton margin.…”

“…The changes in trend in the marginal domain of the EWB Storey and Dalziel, 1987) are more abrupt, and recent work by Jordan et al (2013) suggests that the marginal domain is an extensive shear zone. It is possible that crust similar to the Grenville-age rocks of the Haag Nunataks (Millar and Pankhurst, 1987) underlies the EWB, based on aeromagnetic data (Maslanyj and Storey, 1990;Jordan et al, 2013) and Nd isotope Barrett et al (1986), the Ohio Range on Long (1965), and the Ellsworth Mountains on Collinson et al (1992). The Falkland Islands section is based on figure 4 of Trewin et al (2002), the measured section of the Permian strata; the full thickness of the Bay of Harbours Formation is not illustrated here (the transition to a fluvial environment, if present, has not been documented).…”

Sources and input mechanisms of hafnium and neodymium in surface waters of the Atlantic sector of the Southern Ocean

“…West Antarctica has five crustal blocks, of which three are relevant for this study: the Haag Nunataks (HN), the Ellsworth Whitmore Mountains (EWM) and the Antarctic Peninsula (AAP). The HN represents a small crustal block between the AAP and the EWM consisting of Proterozoic amphibolites and orthogneisses (Millar and Pankhurst, 1987). The EWM form a 415 km long, NNE-SSW trending mountain chain being a terrane once situated at the margin of Gondwana prior to its break-up during the Jurassic (Dalziel, 1992;Storey, 2005).…”

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

“…2b) (Jacobs et al, 2015). At Haag Nunataks within the HEW and on the Falkland Islands ~1 Ga basement rocks similar to those observed in East Antarctica, and unlike those exposed in West Antarctica, crop out (Clarkson and Brook, 1977;Jacobs et al, 1999;Millar and Pankhurst, 1987;Storey et al, 1994). It has been suggested that major transcurrent fault systems of the EAAO allowed tectonic escape of the inferred pre-existing microcontinental fragments from the EAAO interior towards the Paleo Pacific ( Fig.…”