SLOPE MORPHOLOGY ADJACENT TO THE COOL-WATER CARBONATE SHELF OF SOUTH-AUSTRALIA - GLORIA AND SEABEAM IMAGING

A combined GLORIA, Seabeam and high-resolution seismic survey was cond ucted over a selected area of the southern Australian continental marg in. The survey focused on the continental slope immediately seaward of the wide cool-water carbonate shelf, in a region dissected by a suite of large submarine canyons. Examination of the data underscores the s ignificance of mass-wasting processes in the development of slope morp hology. Slump scars and obvious sediment slides are virtually ubiquito us, in many cases being sourced immediately below the shelf break and connecting downslope with erosional channels. The channels themselves possess what appear to be degraded levee banks suggesting possible spi ll-over of turbidity currents which themselves may have been triggered by the upper slope slides. The age of these large-scale sediment move ments remains uncertain, however, and it is currently unclear whether or not they relate to specific sea-levels. A pair of east-trending sca rp-like features dominates the mid-slope region, possibly representing the surface expression of extensional normal faults related to the no rthwestern margin of the Otway Basin.