- ISSN: 2202-0586
- E-ISSN:
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oa Nature and origin of Jurassic volcanism in the Eromanga Basin
- Australian Society of Exploration Geophysicists
- Source: ASEG Extended Abstracts, Volume 2019, Issue 2nd Australasian Exploration Geoscience Conference: Data to Discovery, Dec 2019, p. 1 - 5
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- 01 Dec 2019
Abstract
The Cooper and Eromanga Basins of South Australia and Queensland are the largest onshore hydrocarbon producing region in Australia. Igneous rocks have been documented infrequently within end of well reports over the past 34 years, with a late Triassic to Jurassic age determined rom well data. However, the areal extent and nature of these basaltic rocks were largely unclear. Here, we integrate a variety of subsurface datasets to clarify the nature and origin of igneous rocks preserved within Eromanga Basin sequences overlying the Nappamerri Trough of the Cooper Basin. We recognise mafic monogenetic volcanoes that extend into tabular basalt lava flows, igneous intrusions and, more locally, hydrothermally altered compound lava flows. The volcanic province covers ~7500 km2 and is proposed to have been active between ~180-160 Ma. We name this Jurassic volcanic province the Warnie Volcanic Province after the Warnie East 1 exploration well, drilled in 1985. The distribution of extrusive and intrusive igneous rocks is primarily controlled by basement structure, with extrusive and intrusive igneous rocks elongate in a NW-SE direction. The magmatism is interpreted as a product of extension and intraplate convective upwelling above the subducting Pacific Slab.
