Ice-sheet evolution in James Ross Basin, Weddell Sea margin of the Antarctic Peninsula: The seismic stratigraphic record

摘要

The stratigraphic architecture of the James Ross Basin, NW Weddell Sea continental shelf, shows three major phases of deposition: preglacial, ice-sheet growth, and ice-sheet dominated. The preglacial phase shows stratigraphic sequences that are similar to low-latitude margins. During the ice-sheet growth phase, there is evidence for initial ice-sheet grounding in the southern part of the basin, which migrated in steps northward. Sediment supply was also high during the ice-sheet growth phase. During the ice sheet–dominated phase, both north and south parts of the basin inherited all the classic features indicative of glacial strata: large glacial troughs hundreds of meters deep and tens of kilometers wide, truncation of sequences overlain by chaotic seismic facies and topped with coherent laminated reflections, and an oversteepened continental slope.