The boundary of the Rodinian craton in southeastern Australia

Abstract

Since it was first recognised that all the Pre-Palaeozoic rocks in Queensland lie west of 140°E, there has been considerable debate about the location of the edge in eastern Australia of what later became known as Rodinia. This paper suggests the Lawloit Fault as the present-day eastern edge in southeastern Australia. The Lawloit Fault was recognised in magnetic interpretations as separating rocks with different structural styles, with the older rocks on the western (Rodinian) side. It is interpreted as the boundary between the extensional structures of the Stansbury Basin and the collisional structures of the early Tasman Fold Belt and where the magnetic rocks of the Dimboola Subzone have indented the Rodinian edge. This boundary also fits well with other, independent, data sets including the presence of rift tholeiites in the west as opposed to oceanic basalt in the east, unusual granite chemistry along its southern continuation and the 3-D shear wave seismic modelling. If the Lawloit Fault is the edge of Rodinia, that edge can be traced over at least 300 km in western Victoria.