Geoscience Australia’s annual contribution to the newsletter of the Australasian Palaeontologists - Nomen Nudum

<div>Scientific studies undertaken on core from the Barnicarndy 1 well drilled in 2019 in the onshore Canning Basin in Western Australia as part of the Exploring for the Future program have shown that the well penetrated a thick section of the early Ordovician Nambeet Formation which contains abundant fossils reflective of deposition in an open marine environment. Although the calcareous shales are organically poor (average total organic carbon content 0.17 wt%) processing of 42 drill core samples recovered a plethora of acid-resistant, organic-walled microfossils. Seven core samples with the highest organic content were analysed for their molecular (biomarker) fossils and stable isotopic composition to provide insights into the type of organic matter preserved, and the redox conditions of the sediments during deposition.</div><div><br></div>This Abstract was submitted/presented to the 2022 Australian Organic Geochemistry Conference 27-29 November (https://events.csiro.au/Events/2022/October/5/Australian-Organic-Geochemistry-Conference)

<div>Palynology preparations from 50 samples from several key wells in the South Australian section of the Pedirka Basin were examined for Geoscience Australia. The sampling was done by Carey Hannaford under inspection number 5358 (see table 1 for sample listing). All resulting slides and remaining residue have been submitted to government. The samples were analysed quantitatively with the first 200 specimens in each sample counted and subsequent species simply recorded as present. In this summary report, the results are provided in tabulated form only. Details of the palynomorph assemblages are recorded on StrataBugs distribution charts, with each taxon expressed as a percentage of the entire assemblage (Appendix B). From this information, assignments are made to the palynostratigraphic scheme of Price (1997), as shown in Figures 1 and 2 and summarised in Appendix A.</div><div>Wells included are: Erabena-1, Macumba-1, Mokari-1, Oolarinna-1, Pandieburra-1, Poolowanna-1, Poolowanna-2, Walkandi-1. </div><div>Also see accompanying report by Hannaford and Mantle, 2022: Palynological analysis of infill samples for selected wells in the Northern Territory section of the Pedirka Basin.</div>

macrofossil biostratigraphic analysis of samples taken from Cambrian units in Bradley 1 well

macrofossil biostratigraphic analysis of samples taken from Cambrian units in Todd 1 well

macrofossil biostratigraphic analysis of samples taken from Cambrian units in GSQ Mt Whelan 1 well

This document is a professional opinion, presenting an assessment of the macrofossils present in well CKAD0001, located in the Northern Territory in the Georgina Basin.

Stratigraphic drill hole NDI Carrara 1 was drilled as a collaboration between Geoscience Australia (GA), the Northern Territory Geological Survey (NTGS) and the Mineral Exploration Cooperative Research Centre (MinEx CRC). It reached a total depth of 1751 m in late 2020 and is the first drill hole to intersect the undifferentiated Proterozoic rocks of the Carrara Sub-Basin. It intersected approximately 630 m of Cambrian Georgina Basin sedimentary rocks overlying the ~1100 m of Proterozoic carbonates, black shales and other siliciclastics of the Carrara Sub-Basin succession. The formational assignments of the Georgina Basin succession are preliminary and were assigned in the field. The units intersected comprise the Border Waterhole Formation (~531m to ~630m), which is overlain by the Currant Bush Limestone (~249m to ~531m), which in turn is overlain by the Camooweal Dolostone (0m to ~249m). Of these, only the lower 80% of the Currant Bush Limestone and the entire Border Waterhole Formation were cored. This report presents biostratigraphic results from macrofossil examination of NDI Carrara 1 core samples within the Georgina Basin section.

The upper Permian to Lower Triassic sedimentary succession in the southern Bonaparte Basin represents an extensive marginal marine depositional system that hosts several gas accumulations, including the Blacktip gas field that has been in production since 2009. Development of additional identified gas resources has been hampered by reservoir heterogeneity, as highlighted by preliminary results from a post drill analyses of wells in the study area that identify reservoir effectiveness as a key exploration risk. The sedimentary succession that extends across the Permian–Triassic stratigraphic boundary was deposited during a prolonged marine transgression and shows a transition in lithofacies from the carbonate dominated Dombey Formation to the siliciclastic dominated Tern and Penguin formations. Recent improvements in chronostratigraphic calibration of Australian biostratigraphic schemes, spanning the late Permian and Early Triassic, inform our review of available palynological data and re-interpretation and infill sampling of well data. The results provide a better resolved, consistent and up-to-date stratigraphic scheme, allowing an improved understanding of the timing, duration, and distribution of depositional environments of the upper Permian to Lower Triassic sediments across the Petrel Sub-basin and Londonderry High. <b>Citation:</b> Owens R., Kelman A., Khider K., Iwanec J., Bernecker T. (2022) Addressing exploration uncertainties in the southern Bonaparte Basin: enhanced stratigraphic control and post drill analysis for upper Permian plays. <i>The APPEA Journal</i> 62, S474-S479

Biostratigraphic analysis of macrofossils extracted from samples taken from BMR Mt Isa 1 well