Provenance of glacial–marine sediments under the McMurdo/Ross Ice Shelf (Windless Bight, Antarctica): Heavy minerals and geochemical data

Provenance of Pleistocene sediments in the ANDRILL AND-1B drillcore: Clay and heavy mineral data

“…Licht et al (2005) recognized in East Antarctica the provenance area of western Ross Sea tills, testifying that West-Antarctic ice streams did not advance into the western Ross Sea during the LGM. Damiani and Giorgetti (2008) presented data in LGM-Holocene sediments from Windless Bight where a shift from TAM-to MVG-derived heavy minerals occurred at the LGM transition. In the AND 1-B core, the transition from MVG-to TAM-dominated heavy mineral assemblages at ca.…”

“…Since cold and arid climatic conditions prevailed from at least the Pliocene, clay mineral variations in Pleistocene Antarctic marine sediments directly indicate changes of the source areas which in turn mirror the glacial dynamics on the continent (Ehrmann et al, 1992;Petschick et al, 1996;Ehrmann, 1998;Lucchi et al, 2002;Hillenbrand and Ehrmann, 2005;Damiani et al, 2006). Heavy mineral assemblages in Antarctic marine sediments can also be successfully used to identify different source areas and to reconstruct the dynamics of ice sheets (Angino and Andrews, 1968;Ehrmann and Polozek, 1999;Polozek, 2000;Neumann, 2001;Damiani and Giorgetti, 2008). The aim of this paper is to reconstruct the ice dynamics in the McMurdo region (western Ross Sea) through an integrated clay and heavy mineral study of Pleistocene sediments from a core collected beneath the McMurdo/Ross Ice Shelf in Windless Bight, south of Ross Island (Naish et al, 2007).…”

Early–Middle Miocene (17–14Ma) Antarctic ice dynamics reconstructed from the heavy mineral provenance in the AND-2A drill core, Ross Sea, Antarctica

“…Clinopyroxenes are extremely difficult to differentiate under a petrographic microscope, however, an attempt was made to classify them based on color and cleavage, following previous heavy mineral studies completed around the McMurdo Sound (Polozek and Ehrmann, 1998, Ehrmann and Polozek, 1999, Passchier, 2001Damiani and Giorgetti, 2008). Optically, colored clinopyroxenes were differentiated from colorless clinopyroxenes and broken into groups based on their color and pleochroism.…”

“…Heavy mineral assemblages can be related to their sources through both optical characteristics and chemical composition via SEM-EDS (e.g., Ehrmann and Polozek, 1999;Passchier, 2001;Damiani and Giorgetti, 2008) and can be used to identify changes in source regions of glacial erosion (Gwyn and Dreimanis, 1979;Passchier, 2007). The composition and downcore distribution patterns of the most abundant heavy minerals in the upper 650 m of the core suggest that they derive from six main sources (Table 3): (1) the Ferrar Group, (2) high-grade metamorphic basement rocks, and (3) carbonates and marble, with a wide variety of sources in the upland regions of the Transantarctic Mountains, (4) the Granite Harbour Intrusives, and (5) metasedimentary rocks of low and medium metamorphic grades, exposed along the coast of the Transantarctic Mountains, and (6) the McMurdo Volcanic Group directly to the south of the drillsite (Fig.…”

Geochemical provenance analysis of fine-grained sediment revealing Late Miocene to recent Paleo-Environmental changes in the Western Ross Sea, Antarctica

“…Statistical analyses of geochemical data help in clearly identifying different sources of detrital material (von Eynatten et al, 2003). Previous work in the Ross Sea region has already demonstrated that geochemical studies of sediment cores provide a reliable tool for determining sediment provenance (Hambrey and Barrett, 1993;Licht et al, 2005;Damiani and Giorgetti, 2008;Giorgetti et al, 2009).…”