Uncovering the greater McArthur Basin, Northern Territory Tania Dhu Manager Geophysics and Remote Sensing, Northern Territory Geological Survey www.minerals.nt.gov.au
Why focus on the McArthur Basin? Large, highly prospective, Palaeo- Mesoproterozoic sedimentary basin Hosts the McArthur River Pb-Zn-Ag mine, within the HYC Pyritic Shale Member of the Barney Creek Formation in the Batten Fault Zone The ca 1640 Ma Barney Creek Formation is a significant unconventional hydrocarbon prospect Oil and gas shows in Lamont Pass-3, Cow Lagoon-1 and Glyde-1 ST1 (Armour Energy Ltd) within the Batten Fault Zone Contains the Roper iron field within the 1500-1400 Ma Roper Group Still relatively underexplored, especially away from the exposed stratigraphy of the Batten Fault Zone Extensive new work being undertaken by industry including seismic and drilling Roper iron field Batten Fault Zone Cow Lagoon 1 Lamont Pass-3 Glyde-1 ST1 McArthur River Mine
The greater McArthur Basin Stratigraphic correlations between the McArthur Basin, Birrindudu Basin and Tomkinson Province have been recognised Stratigraphic correlations recognised based on lithostratigraphy, age of tuffaceous units and similar provenance from U-Pb dating of detritral zircons producing maximum deposition ages Interpretation of newly acquired seismic data supports undercover continuity between these basins The interpreted extent of these regions has been informally referred to as the greater McArthur Basin (black line) extends across almost half the Northern Territory however further work is required to: Understand the true extent of the McArthur Basin, Birrindudu Basin and Tomkinson Province and identify any links between them Establish stratigraphic correlations Understand the 3D architecture and structural evolution of the Basin
Current Work - Geophysics Southern McArthur Basin Gravity Survey (funded through the Creating Opportunities for Resource Exploration CORE initiative) 4,618 stations at 4 x 4 km spacing Falcon Oil & Gas Australia Ltd and Santos Limited collaborated to infill areas of interest to 2 x 2 km spacing, 1,657 stations Dunmarra magnetic and radiometric survey scheduled to commence in June Proposed Northern McArthur Basin Gravity Survey dependent on initiative funding
Current Work - Geology Unconventional hydrocarbon potential and metallogenic assessment of shales Petroleum sampling program for source rock analysis, palynology, geochemistry and formation evaluation Metallogenic sampling program for precious and base metals, including geochemical characterisation for evidence of metal mobilisation Unconventional hydrocarbon assessment using the USGS methodology Stratigraphic correlation within the greater McArthur Basin Systematic characterisation of outcropping and drillcore stratigraphy (sedimentology, petrography, biostratigraphy, depositional environment) Compilation of baseline geochemistry, stable isotope and geochronological datasets Correlation of drillcore stratigraphy using the HyLogger TM Applying the HyLogger to identify discrepancies between logged stratigraphy and mineralogy
Current Work 3D Basin Architecture Understanding the structural evolution of the greater McArthur Basin (PGN Geosciences) Interpreting geophysical data to assist in understanding basin architecture and evolution through time Identifying potential growth faults and depocentres 3D model of the McArthur Basin View heterogeneous geophysical and geological data in a single environment to allow a consistent interpretation that addresses all data Using the model to identify discrepancies in the data and areas where more data is required, addressing these issues than creating new model realisations
Summary NTGS is undertaking a range of projects aimed at improving our understanding of the extent and prospectivity of the greater McArthur Basin Current efforts in the basin are producing new data that is feeding into this work In many instances NTGS has been able to work closely with industry with sharing of both closed file data and interpretation The challenge remains producing products in a timely manner that build the regional framework but respect data confidentiality