The Oenpelli Dolerite - a Precambrian continental tholeiitic suite from the Northern Territory, Australia
The Oenpelli Dolerite comprises at least four major sheet-like intrusions up to 250 m thick of continental tholeiitic composition, which have a lateral extent of about 20 000 km^2. The intrusions were emplaced at about 1720 m.y. into Lower Proterozoic metasediments of the Pine Creek Geosyncline, and postdate an 1880 m.y. regional metamorphic event. The intrusions consist of symmetrically differentiated layers of olivine dolerite, minor felsic differentiates, and rare crosscutting gabbroic pegmatites. Within the thicker sheets minor rhythmic layering is found in olivine dolerite. The Oenpelli Dolerite contains normative orthopyroxene and the major and trace element chemistry closely parallels the trends of major continental mafic tholeiitic suites. Projection of the chemical data into the anhydrous CMAS system shows that the rocks crystallised in the pressure range 1 atmosphere to 5 kb. The close match between the observed equilibrium and the 1 atmosphere phase diagrams for dry tholeiitic magmas suggests that the last equilibration of these magmas was at very low pressure. It is concluded that the tholeiitic Oenpelli Dolerite rocks have evolved by polybaric olivine fractionation during slow, or intermittent, uprise from higher magnesia magma generated by partial melting within the upper mantle; plagioclase is an additional liquidus phase at shallow-crustal levels.
Simple
Identification info
- Date (Publication)
- 1978-01-01T00:00:00
- Citation identifier
- Geoscience Australia Persistent Identifier/https://pid.geoscience.gov.au/dataset/ga/80953
- Cited responsible party
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Role Organisation / Individual Name Details Publisher Bureau of Mineral Resources, Geology and Geophysics
Canberra Author Stuart-Smith, P.G.
1 Author Ferguson, J.
2
- Name
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BMR Journal of Australian Geology and Geophysics
- Issue identification
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3:2:125-133
- Point of contact
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Role Organisation / Individual Name Details Custodian Corp
Owner Commonwealth of Australia (Geoscience Australia)
Custodian Commonwealth of Australia (Geoscience Australia)
Voice
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- Geoscientific information
Extent
))
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- Unknown
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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
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GA Publication
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Journal
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- Keywords
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NT
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- Australian and New Zealand Standard Research Classification (ANZSRC)
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Earth Sciences
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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
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4.0
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- License
Resource constraints
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Australian Government Security ClassificationSystem
- Edition date
- 2018-11-01T00:00:00
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- Unclassified
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- English
- Character encoding
- UTF8
Distribution Information
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Role Organisation / Individual Name Details Distributor Commonwealth of Australia (Geoscience Australia)
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- OnLine resource
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Journal article (pdf)
Journal article (pdf)
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pdf
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Resource lineage
- Statement
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Unknown
- Hierarchy level
- Non geographic dataset
- Other
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GA Publication
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Source data not available.
Metadata constraints
- Title
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Australian Government Security ClassificationSystem
- Edition date
- 2018-11-01T00:00:00
- Classification
- Unclassified
Metadata
- Metadata identifier
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urn:uuid/fae9173a-6f96-71e4-e044-00144fdd4fa6
- Title
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GeoNetwork UUID
- Language
- English
- Character encoding
- UTF8
- Contact
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Role Organisation / Individual Name Details Point of contact Commonwealth of Australia (Geoscience Australia)
Voice
Type of resource
- Resource scope
- Document
- Name
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AGSO BMR Journal
Alternative metadata reference
- Title
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Geoscience Australia - short identifier for metadata record with
uuid
- Citation identifier
- eCatId/80953
- Date info (Revision)
- 2018-04-20T06:08:39
- Date info (Creation)
- 2014-06-03T00:00:00
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
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Geoscience Australia Community Metadata Profile of ISO 19115-1:2014
- Edition
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Version 2.0, September 2018
- Citation identifier
- https://pid.geoscience.gov.au/dataset/ga/122551