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Dredging up Mawson: implications for the geology of coastal East Antarctica.

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Truswell, EM (2012) Dredging up Mawson: implications for the geology of coastal East Antarctica. Papers and Proceedings of the Royal Society of Tasmania, 146. pp. 45-56. ISSN 0080-4703

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Abstract

During the 1911–1914 Australasian Antarctic Expedition samples of bottom sediment were dredged from a wide sweep of coastline extending
from the main base at Commonwealth Bay, to the western edge of the Shackleton Ice Shelf. An earlier study showed these sediments
to contain palynomorphs recycled from eroding sedimentary sequences. High concentrations of Permian, Jurassic to Early Cretaceous, and
Cenozoic microfossils were present in three regions of the continental shelf, namely, offshore from the Shackleton Ice Shelf, from Cape
Carr and from close to the Mertz Glacier. The findings of the earlier study are re-evaluated in the light of new information concerning the
bathymetry of sampled areas on the continental shelf, the sub-ice topography of ice shelves and the Antarctic interior, and of sedimentary
processes controlling the movement of palynomorphs on the sea floor. Data from the vicinity of the Shackleton Ice Shelf raise the possibility
of sourcing some recycled material through sub-ice connections with the deep Aurora Subglacial Basin of the interior. From the George V
Basin, west of the Mertz Glacier, new echo-sounding data show the dredges collected lie mostly on the edge of a steep trough parallel to the
coast. Previous suggestions that Jurassic to Cretaceous sequences there correlate with those of the Otway Basin on the Australian margin
are corroborated by recent seismic reflection data showing thick rift and pre-rift sequences offshore from the Adélie and Wilkes coasts. The
relationship of these sequences to putative Mesozoic sequences within the inland Wilkes Basin is uncertain. Limited studies suggest that
recycled palynomorphs in continental shelf sediments may lie close to the sites of their original deposition.

Item Type: Article
Keywords: Royal Society of Tasmania, RST, Van Diemens Land, natural history, science, ecology, taxonomy, botany, zoology, geology, geography, papers & proceedings, Australia, Antarctica, Mawson, dredging, palynomorphs, recycling, continental shelf, ice shelves.
Journal or Publication Title: Papers and Proceedings of the Royal Society of Tasmania
Page Range: pp. 45-56
ISSN: 0080-4703
Copyright Information:

Copyright The Royal Society of Tasmania

Collections: Royal Society Collection > Papers & Proceedings of the Royal Society of Tasmania
Date Deposited: 23 Jun 2015 22:17
Last Modified: 23 Jun 2015 22:17
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