Authors / CoAuthors
Anderson, J. | Carson, C. | Farkas, J. | Klaebe, R. | Grosjean, E. | Hall, T.
Abstract
<div>NDI Carrara 1 is a 1751 m stratigraphic drill hole completed in 2020 as part of the MinEx CRC National Drilling Initiative (NDI). This campaign was a collaboration between Geoscience Australia under the Exploring for the Future program, together with MinEx CRC and the Northern Territory Geological Survey. It is the first drillhole to intersect Proterozoic rocks of the Carrara Sub-basin, a recently discovered depocentre in the South Nicholson region. The drill hole intersected ~625 m of the Paleozoic Georgina Basin, which overlies ~1120 m of Proterozoic carbonates, black shales and siliciclastic rocks, with hydrocarbon shows encountered in both the Paleozoic and Proterozoic sections. Following the completion of the drillhole, a comprehensive analytical program was carried out by Geoscience Australia to better understand the geology of the Carrara Sub-basin and its resource potential.</div><div><br></div><div>Here we present new high-resolution strontium (87Sr/86Sr), carbon (δ13C) and oxygen (δ18O) isotope data from carbonate bearing samples of the Paleozoic Georgina Basin and the Proterozoic Lawn Hill Formation intersected in NDI Carrara 1. The aim of this data acquisition was to provide an improved understanding of the paleo-depositional environments and local/global chemostratigraphy trends recorded in the Carrara Sub-basin. </div><div><br></div><div>The majority of samples show significant alteration and thus caution should be exercised when using this data for assessing primary depositional conditions and contemporary sea-water chemistry. Despite the altered nature of most samples, samples belonging to undifferentiated Georgina Basin preserve 87Sr/86Sr ratios close to that of mid-Cambrian seawater, indicating the sampled intervals of Georgina Basin were likely connected to the global Cambrian ocean. Two small positive δ13C excursions (with positive shift in δ18O) within Georgina Basin samples may coincide with reported mid-Cambrian positive δ13C global marine excursions. </div><div><br></div><div>The least altered samples from the Proterozoic Lawn Hill Formation show more radiogenic 87Sr/86Sr values than the expected value of coeval mid-Proterozoic ocean at ~1600 Ma. These radiogenic 87Sr/86Sr values may reflect (i) influx of terrigenous material into a restricted basin with reduced interaction with the global ocean, or (ii) secondary overprinting by more radiogenic diagenetic fluids.</div> Abstract/Poster submitted and presented at 2023 Australian Earth Science Convention (AESC), Perth WA (https://2023.aegc.com.au/)
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document
eCat Id
148000
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Keywords
- ( Project )
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- EFTF – Exploring for the Future
- ( Project )
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- MinEx CRC – Mineral Exploration Cooperative Research Centre
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- Stratigraphy
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- carbon isotopes
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- strontium isotopes
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- oxygen isotopes
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- NDI Carrara 1
- theme.ANZRC Fields of Research.rdf
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- Stratigraphy (incl. biostratigraphysequence stratigraphy and basin analysis)
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2023-06-28T02:00:00
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Digital poster conference presentation.
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geoscientificInformation
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Australian Earth Science Convention (AESC) 27-30 July 2023 Perth WA
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<div>Poster presenting on Data Release provided in eCat 147988</div>
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[-18.97325, -18.97325, 137.785, 137.785]
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