ALBERT

Beschreibung: The subglacial geology in Wilkes Land, East Antarctica is masked by thick ice and remains largely unexplored. Yet the underlying crustal architecture records evidence of repeated supercontinent cycles and provides the geological template for the evolution of the Antarctic Ice Sheet. Sediment eroded from under the ice is ultimately deposited in the ocean, such that marine sediment can be used to characterise the adjacent subglacial geology. We use detrital grain morphology, geochemistry and isotopic data from a kasten core to construct a new marine sediment provenance record for the continental slope of central Wilkes Land, and provide new isotopic signatures from proximal coastal outcrops for comparison. We establish the source rock type, age and provenance, and the associated transport pathways and mechanisms responsible for detrital sediment input from 23.5 ka to present. A principally igneous source is revealed with dominant age populations between c. 1200-1100 Ma and c. 1600-1300 Ma, characteristic of the proximal Banzare, Nuyina and Wilkes Provinces. The detrital geochronology suggests no change in sediment provenance over the last 23.5 ka, despite major ice sheet retreat during this time. A minor c. 700-500 Ma detrital age population unknown from the central Wilkes region was likely transported westward via icebergs to the core site. These findings broadly correspond with earlier interpretations of the subglacial geology and erosion rates at the base of the ice sheet predicted from two ice sheet models, demonstrating the value of sediment provenance studies for uncovering proximal subglacial geology and reconstructing past ice sheet configurations.

Beschreibung: This comprises supplementary data from "Expression of Millennial-Scale Antarctic Warming Events in the Southern Ocean." and represents 14 sediment records from the Southern Ocean, 30°S - 60°S. These records have had their age models recalibrated and tied to EDC dD on the AICC2012 timescale to facilitate comparison across basins, and in order to create SST stacks for the Atlantic-Indian, Pacific, and Southern Oceans.

Beschreibung: Downcore measurements of iceberg-rafted debris (IBRD) flux and biogenic silica concentrations in kasten core IN2017_V01-A042-KC14 from the continental slope of central Wilkes Land, East Antarctica. The IBRD flux was calculated by multiplying the coarse sand fraction by the linear sedimentation rate and the dry bulk density at each depth interval along the core. All of these values are shown. The biogenic silica concentration is shown as a percentage.

Beschreibung: Pb-Pb ratios, ages and trace element data from detrital feldspars in kasten core IN2017_V01-A042-KC14 from the continental slope of central Wilkes Land, East Antarctica and in-situ feldspars from coastal basement rocks in East Antarctica (Chick Island and Balaena Islets). All data was obtained using laser ablation-inductively-couple plasma mass spectrometry (LA-ICPMS). All ratios and ages are shown with one standard error.

Beschreibung: Neodymium and strontium isotope compositions from four marine Kasten cores recovered from the continental rise of central Wilkes Land, East Antarctica.

Beschreibung: Zr/Rb and K/Ca elemental x-ray fluorescence ratios from four marine Kasten cores recovered from the continental rise of central Wilkes Land, East Antarctica.

Beschreibung: Bulk acid insoluble organic carbon ages from core IN2017_V01-A042-KC14 with calibrated ages shown and their respective depth intervals. Ages were calibrated using Matcal 2.41 and a constant marine reservoir age of 917.5 years.