Basin thickness and tectonic structure of the west Timor collision zone derived from gravity modelling: Implications for hydrocarbon resources

The Malaka and Atambua regions of West Timor, which lie next to Timor-Leste, are one of the least-studied but most intriguing geological locations in the Sunda–Banda forearc system. Even if there are signs of a lot of minerals in the north and possible oil and gas plays in the south, the underlying structure and resource potential are still not well understood. This study combines field geological mapping, ground-gravity surveys, and lab tests to learn more about basin architecture and figure out how likely it is that hydrocarbons will be found. Bouguer anomalies vary from 37 to 192 mGal, defining two distinct zones of high and low density. Using spectral analysis and second vertical derivative (SVD) filtering, we can find a large north-directed thrust fault and limit the depths of sedimentary basins to about 2–3 km. Geochemical tests on sedimentary rock samples show Total Organic Carbon (TOC) values as high as 0.46 wt%, which means the source rock potential is not very good yet there is organic matter present. Combining structural, geophysical, and geochemical data shows that the Malaka basin is a structurally complicated but perhaps useful hydrocarbon system. The traps are controlled by faults, which is similar to fields being studied in nearby Timor-Leste. These results improve the geological model of southern West Timor and give us a new way to plan future exploration.