Potential for Drilling Cainozoic Sediments below the Ekström Ice Shelf, Dronning Maud Land, East Antarctica

• Main Authors: Kuhn, Gerhard, Kristoffersen, Yngve, Eisen, Olaf, Jokat, Wilfried
• Format: Conference Object
• Language: unknown
• Published: 2015
• Subjects: Antarctic; The Antarctic; Weddell Sea; East Antarctica; Dronning Maud Land; Neumayer; Weddell; Ekström Ice Shelf; Wegener Canyon; Antarc*; Antarctica; Ice Shelf; Ice Shelves
• Online Access: https://epic.awi.de/id/eprint/39058/; http://isaes2015goa.in/docs/XII%20ISAES%202015%20Abstract%20Volume.pdf; https://hdl.handle.net/10013/epic.46325

The Explora Wedge (Hinz and Krause, 1982; Hinz et al., 2004) represents a prominent morphological and structural feature of Earth crust in the north eastern Weddell Sea. Marine geophysical data reveal that it constitutes East Antarctica's volcanic rift margin, with seaward dipping reflectors buried below sediments and floating ice shelves on the continental margin of Dronning Maud Land. Using a vibroseis source on the Antarctic continent for the first time, together with regional aeromagnetic data, these new results show the southward extent of the more than 1000 m thick Explora Wedge (EW) volcanic deposit below the Ekström Ice Shelf (Kristoffersen et al., 2014). While up to now the landward extent of the wedge had been less clearly defined, the new data indicates the top of the wedge outcrop to be about 36 km landward off the shelf edge, or 14 km south of Neumayer III station. One target of the geo-scientific studies will be the top of the EW sequence, which represents the final phase of the initial continent break up and is presumed to be of an Upper Jurassic age. Genesis, magma differentiation, and precise age of the EW volcanics are largely unknown and high-ranking research objectives. The upper boundary of the EW forms a distinct unconformity to the overlaying younger, wedge-shaped sedimentary unit, which reaches about 800 m in thickness close to the Neumayer III station. The age of these sediments is unknown and could be all from Mesozoic to Recent. Considering this largely unexplored Antarctic continental margin, any high latitude palaeo-environmental information about the Mesozoic und lower Cainozoic greenhouse world prior to the start of Antarctic glaciation, the onset of glaciation, and up to the glacial/interglacial variability of the East Antarctic Ice Shield during the Quaternary can best be gathered through drilling at the proposed site. Perhaps we will be able to drill one never reached target of former ODP Leg 113, the Cretaceous black shales that sparsely were dredged from the scarps of the Wegener Canyon close by (Fütterer et al. 1990).