The structure and origin of the Strand Moraines, McMurdo Sound

Geological work on the Strand Moraines, an area believed to be partly grounded ice cored moraine, that may be a relic of the Last Glaciation 20,000-50,000 years ago, was conducted. A study to account for the origin of the moraines and to relate this to the Antarctic Ice Sheet History was conducted. The orientations of the internal ice structure and ice bound sediment layers was structurally mapped as well as the orientations of ice cracks and lineaments depicted by continuous lag covered ice mounds. Ice samples were collected for oxygen isotope analysis to determine the origin of the ice. Debris was sampled from the present moraine and internal debris. Present moraine appeared as a log on the surface of the ice body. It was examined in terms of thickness and analysed in relation to ablation rate and mineralogical composition. Internal debris occurs as sediment bands within ice layering and is exposed as outcrops on the slopes of ice mounds. Qualitative estimations of compositions were made and related to ablation rate and lag thickness. Present day weathering and hydrological activities acting on the area were observed to relate to structure and ice bound debris thickness and distribution.