Late Silurian or Early Devonian corals from the continental slope off southern New South Wales

Abstract

Latest Silurian or Early Devonian tabulate corals have been recovered in a dredge haul from submarine bedrock at a water depth of 2620 – 2155 m on the continental slope off southern New South Wales 45 km east of Tuross Heads from the submerged and unexplored part of the eastern Lachlan Orogen. The corals have been identified as latest Silurian to Early Devonian taxa, Favosites gothlandicus and Squameofavosites squamuliferus forma nitidus. The presence of shallow water deposits containing these forms indicates that a crustal thickening event or events took place near the end of Silurian or early in Devonian time in the eastern Lachlan Orogen east of the present coastline. This occurred well after the end of subduction in Early Silurian time which is marked by the welding of the Cambrian — Late Ordovician Wagonga Group accretionary wedge or collided terrain on to the eastern margin of the orogen and significantly earlier than the emplacement of the Moruya Suite granites in Middle Devonian time.