Abstract:
Sediments recovered from seven Last Glacial Maximum grounding lines sites, around
the Antarctic Peninsula, were analyzed using micromorphology. This is the first
evidence that grounding line sediments from around the Antarctic Peninsula have
complex deformational histories and subglacial origins. It was determined that
grounding zone wedge contain multiple units, or diamicton layers, with homogenized
boundaries. The multiple diamicton units / layers are due to the accretionary formation
of a grounding line wedge. All the sediments were deposited via deformation, and
continual reincorporation, homogenization of lower diamicton layers by upper
diamicton layers produced what macroscopically appeared to be a single massive
diamicton unit. The morainal ridge that was sampled, alternatively, is composed of a
single unit, or diamicton layer, that was subglacial in origin and believed to have been
pushed out to form a ridge that was subsequently deformed via glacial push.
