Abstract The Timor Orogen comprises the island of Timor, a narrow offshore area to the north and a wider offshore fold-and-thrust belt to the south. This orogen formed by jamming and subsequent collision of the Banda Sea subduction system by the Australian Plate. The BandaSeis seismic survey has revealed excellent images of the deep-water fold-and-thrust belt. Seismic interpretation of the dataset demonstrated structural and tectonic features not previously described, including regional geological features on the Australian continental crust and two regional NE–SW sinistral strike-slip faults, and a prominent Middle Permian palaeogeographical high (Timor Plateau). Moreover, since the Middle–Late Triassic and Middle Jurassic, the two NE-trending strike-slip faults governed the formation of the West Timor and Cova-Lima sub-basins. The location along the Australian margin plays a dominant role in controlling the structural style and shaping of the Timor Orogen. Vertical loading and the southerly motion of the orogenic wedge are the main driving forces responsible for its building, illustrating a thin-skinned tectonic framework. Thrust faults nucleate in a forward-breaking sequence in the motion of thrust transport, with younger thrusts developing in front of older thrusts. Most of the collisional deformation has been classified into two styles: shallow thin-skinned and deep-seated deformation.

Abstract The complicated geology of the Banda region results from complex collision between the Eurasia, Australia and Pacific plates, ongoing in the region since the Late Oligocene but particularly in the study area since the Middle Miocene (from 15 Ma). Regional 2D broadband seismic data have provided improved imaging of Mesozoic and Cenozoic sedimentary successions in the region. The region comprises the deep and ultra-deep Banda Sea enclosed by a magmatic inner arc and an outer deformed zone, comprising a series of orogens. This outer orogenic zone comprises islands with extended and sometimes hyperextended continental crust, a series of marginal foredeeps and intervening fold-and thrust belts. This paper illustrates how the offshore fold-and-thrust belts that bound the fore-deeps change in size, shape and degree of basement reactivation in a clockwise sense around the Banda Arc.

Abstract The New Zealand Exclusive Economic Zone (EEZ) contains at least six large deep water basins: the deep water Taranaki basin, the Raukumara basin, the Pegasus basin, the Head of the Bounty trough, the Great South basin and the Solander trough. Structural styles vary from rift basins through strike-slip dominated basins to major accretionary prisms. Source rocks encountered include coal measures, black marine shales, and lacustrine facies. Sedimentary thicknesses, heat flow studies, and basin modeling supported by production and numerous seeps in the shelf and onshore, suggest that these basins may be prolific hydrocarbon producers in the future. Recent developments suggest that the most promising of these basins is the deep water Taranaki basin, outboard of New Zealand’s only producing basin to date. The petroleum histories of most of these basins began with the Late Cretaceous break-up of Gondwana and the formation of rift basins. In onshore New Zealand and on the continental shelf, many of the source rocks for the productive Taranaki basin were deposited at this time. The earliest sediments to be deposited were commonly fluvial, lacustrine, deltaic and nearshore facies followed by an increasing marine influence as the region foundered through the Paleogene. The Neogene saw the formation of the present plate boundary and the emergence of New Zealand in response to plate collision. Many of the more spectacular structures in the New Zealand sedimentary basins were formed during the Neogene. Meanwhile, the deep water basins away from the plate margin continued a quieter development. Some inversion occurred, but not to the extent of the nearshore and onshore regions. This relatively gentle structural evolution increased the likelihood of discovering large hydrocarbon fields in unbreached structural traps.