The Ross Sea continental slope presents morphological peculiarities which are in part structural, in part due to the advances and retreats of the ice cap, and in part influenced by the interaction between bottom waters that come from the continental shelf and currents driven by circum-Antarctic circulation. The inlets that are located at E and W of the Iselin Bank represent two of the major supply conduits of cold and dense bottom water towards the circum-Antarctic water today, as well as the pathways of sediment from the continental shelf to the deep ocean. In particular, depositional and erosive features characterize the continental slope to the E of Iselin Bank. The Hillary Canyon and its channel-levee system is the dominant feature in this area. Existing seismic and sedimentary data, which are at rare intervals, show that the canyon was active from the late Miocene on. XRD and XRF core scanner analyses have been performed on three cores from this area. XRD powder analyses on the whole-rock showed that the mineralogy is mainly represented by quartz and feldspars (both plagioclase and Kfeldspars) with subordinate clay minerals/micas. Different source areas could be distinguished in both ways, within a single core and in a comparison between the different cores by interpreting the Al, Si, Ti, Zr content as well as the Ca/K and Ba/Sr ratios.

Mineralogy and geochemistry of cores from the Ross Sea: A comparison to find out possible source areas

LENAZ, DAVIDE;COLIZZA, ESTER
2013

Abstract

The Ross Sea continental slope presents morphological peculiarities which are in part structural, in part due to the advances and retreats of the ice cap, and in part influenced by the interaction between bottom waters that come from the continental shelf and currents driven by circum-Antarctic circulation. The inlets that are located at E and W of the Iselin Bank represent two of the major supply conduits of cold and dense bottom water towards the circum-Antarctic water today, as well as the pathways of sediment from the continental shelf to the deep ocean. In particular, depositional and erosive features characterize the continental slope to the E of Iselin Bank. The Hillary Canyon and its channel-levee system is the dominant feature in this area. Existing seismic and sedimentary data, which are at rare intervals, show that the canyon was active from the late Miocene on. XRD and XRF core scanner analyses have been performed on three cores from this area. XRD powder analyses on the whole-rock showed that the mineralogy is mainly represented by quartz and feldspars (both plagioclase and Kfeldspars) with subordinate clay minerals/micas. Different source areas could be distinguished in both ways, within a single core and in a comparison between the different cores by interpreting the Al, Si, Ti, Zr content as well as the Ca/K and Ba/Sr ratios.
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Utilizza questo identificativo per citare o creare un link a questo documento: http://hdl.handle.net/11368/2768737
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