Grounding-zone wedges on the northern Larsen shelf, Antarctic Peninsula

Prominent quasi-linear or lobate wedge-shaped depositional sedimentary landforms, termed grounding-zone wedges (GZWs), are distributed widely on polar continental shelves. They are regarded as a product of the deposition of mainly subglacially-transported sediment at the grounding-zone of modern and palaeo ice sheets and ice streams (e.g. Shipp et al. 1999; Ottesen et al. 2005; Horgan et al. 2013). GZWs vary in shape, dimensions and regional distribution across the continental shelf, where they can form single or multiple and widely- or closely-spaced depositional features. The presence of these landforms is used to delimit the maximum and retreat positions of former ice-sheet margins on high-latitude continental shelves (e.g. Shipp et al. 1999; Ottesen et al. 2005). During the Late Glacial transition, retreat of the Antarctic Peninsula Ice Sheet that covered the shelf of the NE Antarctic Peninsula during the Last Glacial Maximum (LGM) produced several distinctive grounding-zone landforms (Evans et al. 2005).