Publication Date:
2018-08-10
Description:
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).
Repository Name:
EPIC Alfred Wegener Institut
Type:
Conference
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notRev
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