While the history of the Western Ross Sea (WRS) is quite well understood, the history of the Eastern Ross Sea (ERS) is still affected by lacks and uncertainties, in particular the Last Glacial Maximum (LGM) – Holocene transition. A multidisciplinary approach is very useful to reconstruct the evolution of the WAIS since the LGM and sedimentary dynamics in the Glomar Challenger Basin (ERS). This is a crucial site because it is close to the WRS, characterized by different morphologies and different mechanisms of the ice sheet retreat. The Glomar Challenger is also connected to the Hillary Canyon, one of the main drainage channel of the continental shelf, which favors the inflow and outflow of water masses. A transect of five gravity cores were collected from the inner shelf, near the actual position of the Ross Ice Shelf (RIS) to the shelf break during several PNRA expeditions. A combination of sedimentological, micropaleontological and geochemical analyses (XRF, IPSO25) have been performed. Gravity cores dating have been obtained using Accelerator Mass Spectrometry (AMS) on organic matter. Here we presents the preliminary results of this study. Three facies have been recognized, from the oldest to the most recent: 1) Glacial: heterogeneous over-compacted sublacial diamicton; 2) Glacial marine: sub-ice shelf sediments characterized by the high presence of Ice Rafted Debris (IRD) and sparse carbonate foraminifera; 3) Holocene: muddy sediments in the inner shelf, coarse sediments in the outer shelf; both are characterized by the presence of agglutinants foraminifera, radiolarians and sponge spicules
LGM - Holocene transition in the Glomar Challenger Basin (Eastern Ross Sea, Antarctica): preliminary results
Geniram A.
;Colizza E.;Melis R.;Torricella F.;
2022-01-01
Abstract
While the history of the Western Ross Sea (WRS) is quite well understood, the history of the Eastern Ross Sea (ERS) is still affected by lacks and uncertainties, in particular the Last Glacial Maximum (LGM) – Holocene transition. A multidisciplinary approach is very useful to reconstruct the evolution of the WAIS since the LGM and sedimentary dynamics in the Glomar Challenger Basin (ERS). This is a crucial site because it is close to the WRS, characterized by different morphologies and different mechanisms of the ice sheet retreat. The Glomar Challenger is also connected to the Hillary Canyon, one of the main drainage channel of the continental shelf, which favors the inflow and outflow of water masses. A transect of five gravity cores were collected from the inner shelf, near the actual position of the Ross Ice Shelf (RIS) to the shelf break during several PNRA expeditions. A combination of sedimentological, micropaleontological and geochemical analyses (XRF, IPSO25) have been performed. Gravity cores dating have been obtained using Accelerator Mass Spectrometry (AMS) on organic matter. Here we presents the preliminary results of this study. Three facies have been recognized, from the oldest to the most recent: 1) Glacial: heterogeneous over-compacted sublacial diamicton; 2) Glacial marine: sub-ice shelf sediments characterized by the high presence of Ice Rafted Debris (IRD) and sparse carbonate foraminifera; 3) Holocene: muddy sediments in the inner shelf, coarse sediments in the outer shelf; both are characterized by the presence of agglutinants foraminifera, radiolarians and sponge spiculesPubblicazioni consigliate
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