Abstract:
Granite Harbour can be considered a 'closed basin' which collects sediment deposited from the Mackay Glacier Tongue. Study of this sedimentation system enables a more precise interpretation of the marine glacial contribution to recent McMurdo Sound - Ross Sea sediments and the older Cenozoic sediments underneath. A study to identify the main sources, transport processes and sinks, and to test our
... conceptual sedimentry model for the system was initiated. In an attempt to determine both the rate of movement and amount of plastic deformation of the Mackay Glacier Tongue, a network of poles was established up and down the glacier from the grounding line. The poles were resurveyed over three seasons. Annual surface ablation was measured from pole positions. 25 positions were measured/surveyed on the glacier and tongue in an attempt to establish both elevation profiles across the grounding line and the position of the snout. Samples of icebergs, containing layers of debris charged ice, were taken for ice density and measurment of pebble orientation and shape. Englacial debris and lag of a terminal ice core moraine from the southern ice stream were sampled for textural comparison with the debris charged icebergs. Water samples were taken from sites in Granite Harbour to identify suspended particulates. Mineral identification was made optically. Sediment traps were deployed to catch sediment settling out of the water column to determine sedimentation rate. Mineralogical and textural analysis were completed. Undisturbed bottom sediment was collected for detailed paleontological and sedimentological studies. Two cores were collected from a crack about the grounding line and another from in front of the snout and were related spatially and possibly temporally. Seafloor sediments were obtained from a cruise vessel, USCGS GLACIER for analysis and sphincter cores were collected within Granite Harbour for analysis by x-ray, textural and mineralogical composition. Currents were attempted to be measured by indirect methods of measuring salinity changes and suspended particulate concentrations within a vertical water column profile. The abundance of aeolian debris on the sea ice was measured at eight sites within Granite Harbour. 
