Publications

Quartz-rich sandstones in the outer Banda Arc Islands are the equivalent of Mesozoic sandstones along the northern Australian margin and are important potential hydrocarbon reservoirs. They have been exposed by on-going collision of Australia and Asia, resulting in the opportunity to study their provenance. Previous studies suggest that rivers draining Australia will have provided most sedimentary input. There have been suggestions of a northern provenance for some Timor sediments. Conventional light mineral plots of sandstones from the samples of the various Banda Arc islands typically show recycled orogen and/or continental block as origin, consistent with an Australian source. However, many of the sandstones are texturally immature. Many samples also contain volcanic quartz and volcanic lithic fragments. Heavy mineral assemblages dominated by rounded ultra-stable minerals are typical for most samples. However these are commonly mixed with angular grains. Most samples predominantly contain heavy minerals from acidic igneous and metamorphic rocks. A few samples contain grains from mafic or ultramafic origin. Detrital zircon (LA-ICP-MS) U-Pb ages range from Archean to Mesozoic, but variations in age populations indicate differences in source areas along the Banda Arc in locality and time. In the Tanimbar Islands and Babar, sediment came from both Australian basement and acidic igneous rocks from the Bird’s Head. Sandstones in Timor show a difference in provenance from east to west. The east contains a greater acidic igneous signature, whereas the west is more dominated by metamorphic sources in the Triassic and suggests better connectivity to continental Australia from the Jurassic to Cretaceous. Cretaceous zircon ages, heavy minerals and immature textures in rocks from Sumba suggest that they are mainly derived from metamorphic sources. Mesozoic to Archean zircons from Sumba suggest derivation from Australian crust that had collided in Sulawesi during the Cretaceous.