| Summary: | Minéralogie and textural data examined in this study suggest that glacial ice derived from the present day Cook Ice Shelf extended to the edge of the d'Urville Sea continental shelf. Based upon diatom floras and sedimentary relationships, this event took place within the last 18 years. As part of this glacial maximum, basal tills and glacial marine sediments were deposited over an irregular subglacial surface. Extensive redeposition of eroded material took place in the middle and outer portions of the continental shelf. Retreat of glacial ice was relatively rapid and was associated with widespread deposition of a thin residual glacial marine unit and turbidity current deposits in the far western and eastern parts of the region. Today, sedimentation on the continental shelf of the d'Urville Sea is controlled by biogenic and physical oceanographic processes. Deposition of ice-rafted detritus from icebergs undoubtably occurs but is relatively insignificant. Relict glacial and glacial marine deposits are being reworked on the outer and eastern portions of the shelf. This reworking is associated with an impinging Circumpolar Deep Water Mass and a westerly flowing geostrophic current. Deeper, inner portions of the continental shelf are not exposed to these currents and relatively rapid deposition of siliceous muds is occuring in these areas. Depostion of such laminated muds may be seasonal and is most likely related to the production of Saline Shelf Water.
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