b'CommitteesASEG newsBrowse Basin from basin-to-wellbore scale using multiple geoscience approaches. In this year, the project focused on the regional geology through the examination of basin-wide record of Mesozoic igneous and tectonic activity.Work performed during 2022: We evaluated the basin architecture, igneous rock types and their distributions, their petrophysical characteristics, and their correlation to seismic facies using over 100 exploration/appraisal wells and regional 2D/3D seismic data. Basin-wide Mesozoic palaeo-environmental maps were also interpreted, which illustrate the evolution of igneous rock distribution and types through geological time (Figure 3). Our analyses Figure 2.Lithostructural geophysical interpretation of the study area filtered by overarching lithologicalindicate that although igneous activity domain. has sporadically continued within the basin throughout the Mesozoic, the and published field mapping) utilisedoverprinting of the Charters Towersmost aggressive period of magmatism to categorise lithologies and informProvince by the Connors Subprovinceoccurred during the Middle Jurassic; a the overarching domains presented inor temporally separated periods oflarge part of the outboard basin was Figure 2. This interpretation found thatsubsequent deformation. covered by thick volcanic sequences Benambran deformation produced ENE- (e.g. 447 m in Warrabkook-1, 320 m WSW-trending sinistral strike-slip faultsRF22P01. University of Adelaide PhDin Kontiki-1, and 1117 m in Grace-1), in the Charters Towers domain whichStudent Kosuke Tsutsui (Supervisors Profmainly consisting of accumulations were overprinted by the subsequent N-SSimon Holford, Dr Mark Bunch, A/Profof tabular or compound lava flows. In to NNW-SSE eastward-dipping thrustRos King, Adj/Prof Ken McClay, Prof Nickcontrast, igneous rocks in the central faults associated with the early Hunter- Schofield). part of the basin (the Caswell Sub-Bowen Orogeny and the accretion ofGeophysical-geomechanicalbasin) are commonly found within the Connors Arc system. An ensuingcharacterisation of igneous rocks in themore terrigenous sedimentary facies re-activation along ENE-WSW sinistralBrowse Basin: implications for exploration,(e.g. coal beds). They often occur faults was observed and is interpreteddevelopment, and gas storage in volcanic- as strongly altered volcaniclastic to indicate localised migration to ~NE- rich basins. sediments, which are observed in cores SW directed shortening during the latesuch as the Calliance-3, Brecknock-4, Hunter-Bowen Orogeny. Project goal and annual plan: The majorDinichythys North-1, where it is rare goal of this project is to investigate theto observe stacks of unaltered lava A series of regional surficial curvaturesimpact of igneous rocks on exploration,flows. Subsequent episodic magmatism evident in the structural grain ofdevelopment and gas storage in theduring the Berriasian resulted in a northeast Queensland are defined by remanent Late Proterozoic to Early Palaeozoic basement sequences and metamorphic belts. High-resolution (40 m) aeromagnetics and satellite imagery reveal intersecting NNW-SSE and WSW-ENE structural trends in the enigmatic Inkerman Metamorphics (Connors Subprovince), proximal to the location of the fold axial trace of an inferred orocline. Targeted field mapping and petrophysical data was collected at Inkerman Station and used to examine evidence for this potential orocline, constrain the resolution of the lithostructural interpretation and to ground-truth the geophysics. Geological field mapping reveals that no evidence of oroclinal bending is preserved in the Inkerman Metamorphics. Rather, the change in trend perhaps reflectsFigure 3.Interpreted palaeo-environment and volcanic provinces of the Browse Basin9 PREVIEW APRIL 2023'