Product catalogue
Defining a chemostratigraphic framework for the Officer Basin. Inorganic and stable isotopic analyses of ten petroleum wells from Western Australia and South Australia
As part of the Exploring for the Future (EFTF) program, a chemostratigraphic framework for the Officer Basin was developed that correlates inorganic geochemical sequences between exploration wells. The Officer Basin spans 525,000 km<sup>2</sup> across Western Australia and South Australia, where it remains an unproven frontier basin which has seen little exploration. The objective of this study was to undertake a bulk rock elemental chemostratigraphy study on ten historic wells in order to better correlate the Neoproterozoic and Cambrian sections. Ten study wells, five from Western Australia and five from South Australia, were selected, and core (241) and cuttings (1,245) samples were acquired from their respective state core libraries. All samples were analysed using Inductively Coupled Plasma-Optical Emission Spectrometry (ICP-OES) and Inductively Coupled Plasma-Mass Spectrometry (ICP-MS), resulting in quantitative data for 50 elements. The approximate proportions of dolomite, clastics, halite and anhydrite for the samples were derived using stoichiometric geochemical calculations. Halite was identified in some formations based on mud log and wireline data, but was not always preserved in the cuttings samples. This non-detection of halite resulted in poor matches between the wireline gamma ray (GR) and ChemGR profiles for halite-bearing units in some wells (e.g. Dragoon-1, Mulyawara-1, and Yowalga-3). Key element and ratios utilised to subdivide the strata were principally chosen to highlight changes in sediment provenance, climatic, and organic matter changes, as they typically have the best correlation potential over a greater distance.
The stratigraphy within the study wells has been subdivided into eight chemostratigraphic mega-sequences referred to as MS1 to MS8, which are further subdivided into a total of twenty-four sequences. Mega-Sequences MS1 to MS4 broadly correspond to the published Neoproterozoic–Cambrian Centralian Supersequences (CS1 to CS4). While overall there is broad agreement between these two schemes, there are also sections where the stratigraphy has been reassigned. For example, within Kutjara-1, the section previously assigned to Centralian Supersequence CS2, and equivalent to the Cryogenian Tapley Hill Formation, is assigned to Mega-Sequence MS3 (not MS2). Within MS4, the lithostratigraphically defined members of the Observatory Hill Formation show some significant variation to the chemostratigraphy, with differences occurring within sequences MS4-S3, MS4-S4 and MS4-S5 (e.g. Birksgate-1; Trainor Echo-1). Mega-Sequence MS6 encompasses the Mount Chandler Sandstone in Trainor Echo-1 in the east and the lithological lateral equivalent Lennis Sandstone in Lungkarta-1/ST1 and Yowalga-1 in the west; however, these two argillaceous sandstones are chemically distinct.
Carbonate-containing samples from three wells (Birksgate-1, Yowalga-3, and Giles-1) were analysed for their δ13Ccarb and δ18Ocarb isotope signature using Isotope-Ratio Mass Spectrometry (IRMS), with results from the least altered carbonates being of sufficient quality to attempt preliminary age dating. Comparison of the Officer Basin isotope data to global type sections enabled tentative correlation of the Yowalga-3 carbonates to the Tonian and late Ediacaran, and the Birksgate-1 carbonates to the early Cambrian.
The geochemistry analyses from 10 basin-wide wells provide a robust dataset that has been used to confirm which sections correlate within the existing lithostratigraphic and sequence stratigraphic framework. This study also highlights where further work needs to be undertaken to elucidate the spatial and temporal relationships of some Cryogenian and early Cambrian sections across the entire basin, given that rocks of these ages contain both potential source and reservoir rocks for petroleum generation and accumulation.
Simple
Identification info
- Date (Creation)
- 2021-05-10
- Date (Publication)
- 2022-04-27T02:34:29
- Citation identifier
- Geoscience Australia Persistent Identifier/https://pid.geoscience.gov.au/dataset/ga/145387
- Citation identifier
- Digital Object Identifier/http://dx.doi.org/10.11636/Record.2022.007
- Cited responsible party
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Role Organisation / Individual Name Details Author Munday, S.
Chemostrat Australia Pty. Ltd. External Contact Author Edwards, D.S.
External Contact Author Chandra, J.
Chemostrat Australia Pty. Ltd. External Contact Author Wang, L.
MEG Internal Contact Author Forbes, A.
Chemostrat Australia Pty. Ltd. External Contact Author Riley, D.
Chemostrat Australia Pty. Ltd. External Contact Author Anderson, J.
Office of the Chief Scts Internal Contact Author Grosjean, E.
MEG Internal Contact Author Bailey, A.
MEG Internal Contact Author Boreham, C.J.
External Contact Publisher Commonwealth of Australia (Geoscience Australia)
Voice
- Name
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Record
- Issue identification
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RECORD 2022/007
- Purpose
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Correlation of Neoproterozoic and Cambrian rocks across the Officer Basin.
- Status
- Completed
- Point of contact
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Role Organisation / Individual Name Details Point of contact Commonwealth of Australia (Geoscience Australia)
Voice Point of contact Edwards, D.S.
External Contact Resource provider Minerals, Energy and Groundwater Division
External Contact
- Spatial representation type
- Topic category
-
- Geoscientific information
Extent
Temporal extent
- Time period
- 2021-03-01 2022-03-01
Extent
))
- Maintenance and update frequency
- As needed
Resource format
- Title
-
Product data repository: Various Formats
- Website
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Data Store directory containing the digital product files
Data Store directory containing one or more files, possibly in a variety of formats, accessible to Geoscience Australia staff only for internal purposes
- theme.ANZRC Fields of Research.rdf
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GEOCHEMISTRY
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Inorganic Geochemistry
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EARTH SCIENCES
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Isotope Geochemistry
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- Theme
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Chemostratigraphy
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- Feature type
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Officer Basin
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- Project
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Exploring for the Future
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- Temporal
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Neoproterozoic
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- Temporal
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Cambrian
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- Keywords
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Published_External
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Resource constraints
- Title
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Creative Commons Attribution 4.0 International Licence
- Alternate title
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CC-BY
- Edition
-
4.0
- Access constraints
- License
- Use constraints
- License
Resource constraints
- Title
-
Australian Government Security ClassificationSystem
- Edition date
- 2018-11-01T00:00:00
- Classification
- Unclassified
Associated resource
- Association Type
- Was informed by
- Title
-
Bulk Rock Stable Isotopes Database Table
- Citation identifier
- 149386
- Citation identifier
- db40a54b-3d69-45ce-bfe4-94d20f481e93
- Language
- English
- Character encoding
- UTF8
Distribution Information
- Distributor contact
-
Role Organisation / Individual Name Details Distributor Commonwealth of Australia (Geoscience Australia)
Voice
- OnLine resource
-
Download the Record (pdf) [18.4 MB]
Download Record (pdf) [18.4 MB]
- Distribution format
-
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pdf
- File decompression technique
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None
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- OnLine resource
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Download Appendix 2 (xlsx) [2.7 MB]
Download Appendix (xlsx) [2.7 MB]
- Distribution format
-
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xlsx
- File decompression technique
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None
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- OnLine resource
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Download Figures (Hi-Res) (zip) [48.6 MB]
Download Figures (Hi-Res) (zip) [48.6 MB]
- Distribution format
-
-
- File decompression technique
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Unzip
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Resource lineage
- Statement
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Release of data and interpretation of the inorganic and isotopic results obtained for 10 wells from the Officer Basin by Chemostrat Australia under contract to Geoscience Australia
Reference System Information
- Reference system identifier
- EPSG/GDA94 / Geoscience Australia Lambert (EPSG:3112)
Metadata constraints
- Title
-
Australian Government Security Classification System
- Edition date
- 2018-11-01T00:00:00
- Classification
- Unclassified
Metadata
- Metadata identifier
-
urn:uuid/1f8d63bb-a787-43ee-afdd-8faab83afbf2
- Title
-
GeoNetwork UUID
- Language
- English
- Character encoding
- UTF8
- Contact
-
Role Organisation / Individual Name Details Point of contact Commonwealth of Australia (Geoscience Australia)
Voice Owner Edwards, D
Geoscience Australia Internal Contact Point of contact Edwards, D.
MEG Internal Contact
Type of resource
- Resource scope
- Document
- Name
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GA publication: GA Record
Alternative metadata reference
- Title
-
Geoscience Australia - short identifier for metadata record with
uuid
- Citation identifier
- eCatId/145387
- Date info (Creation)
- 2019-04-08T01:55:29
- Date info (Revision)
- 2019-04-08T01:55:29
Metadata standard
- Title
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AU/NZS ISO 19115-1:2014
Metadata standard
- Title
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ISO 19115-1:2014
Metadata standard
- Title
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ISO 19115-3
- Title
-
Geoscience Australia Community Metadata Profile of ISO 19115-1:2014
- Edition
-
Version 2.0, September 2018
- Citation identifier
- https://pid.geoscience.gov.au/dataset/ga/122551