THE TECTONIC DEVELOPMENT OF TIMOR: A NEW MODEL AND ITS IMPLICATIONS FOR PETROLEUM EXPLORATION

Abstract

It is argued that the two current tectonic models for Timor, namely the overthrust model and imbrication model do not adequately explain some recent observations, such as the continuity of the Australian continental crust underneath Timor, the lack of field evidence for pervasive imbrication or large scale horizontal thrusting, the absence of convincing evidence for allochthonous masses and the 'palaeomagnetic similarity between the Permian of Timor and Australia. An alternative model is developed in which the continental margin of Australia, when reaching the subduction zone, is decoupled from the down-going slab and, as a result of isotatic rebound, is weakly imbricated. Material transfer across the plate margin is limited to surficial olistostrome mass transport, which could have caused some thrust faulting in the younger Tertiary basins in the south. This model presents a simpler structural geometry and predicts continuity with the Sahul Shelf.