The Gippsland Basin deep seismic reflection/refraction grid

Abstract

A regional 1650 km grid of deep seismic reflection data and complementary ship-shore refraction data is being used to study the deep structure of the Gippsland Basin. Preliminary results indicate that within the Cental Deep of the basin there appears to be little development of highly rotated fault blocks that are characteristic of most rift basins. On this basis we suggest that the basin may be of strike slip or transtensional origin. Periodic movements of the sinuous boundary fault systems, may have lead to intra-Latrobe traps, with the culmination of these movements in the early Tertiary forming the 'Top Latrobe' anticlines. Such movements appear to have been right-lateral. The fault systems which bound the basin extend downwards to the lower crust. A band of high amplitude events at mid to lower crustal levels may represent anastomosing fault systems at a detachment zone.