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Surface geology of Australia 1:1,000,000 scale, Western AustraliaNote: This metadata describes the dataset in accordance with the ANZLIC (Australia New Zealand Land Information Council) Core Metadata Guidelines Version 2. Dataset citationANZLIC unique identifier: ANZCW0703012215 Title: Surface geology of Australia 1:1,000,000 scale, Western Australia CustodianCustodian: Geoscience Australia Jurisdiction: Australia DescriptionAbstract: The 1:1 million-scale `Geology of Western Australia' dataset has been compiled largely from the latest published 1:250,000 scale geological maps, augmented by more recent 1:100,000 scale and regional compilation maps. Most of Western Australia is covered by poorly consolidated Cenozoic regolith, mainly sand plains and dunes, lake deposits, and colluvium, with lesser silcrete, calcrete, and laterite. Bedrock geological provinces in WA include the Pilbara Craton, Capricorn Orogen, Gascoyne Block, Northampton Complex, Hamersley/Ashburton Basins, and Carnarvon Basin in the west; Yilgarn Craton, Leeuwin Complex, and Perth Basin in the southwest; Albany - Fraser Province and Bremer and Eucla Basins in the south; Musgrave, Arunta, and Granites - Tanami Blocks and Birrindudu, Amadeus, and Officer Basins in the east; Halls Creek Province and Kimberley, Ord, Bonaparte, and Canning Basins in the north; and the Paterson Province and Proterozoic basins of the Bangemall region (Yerrida, Bryah, Padbury, Earaheedy, Scorpion, Edmund, Collier, Salvation basins) in the centre. The oldest rocks, in the northwest Yilgarn Craton, are gneisses formed by metamorphism of igneous felsic to mafic crust (3.7-3.5 Ga), accompanied by smaller amounts of sedimentary rocks of igneous derivation. These formed probable basement to extensive greenstone sequences (3.7-2.5 Ga) that were intruded by voluminous granites at 3.5-2.6 Ga (Pilbara and Yilgarn Cratons). The junction of these two regions became a locus for extensive basaltic volcanism, followed by shallow-water clastic, carbonate, and iron sedimentation (Hamersley/Ashburton Basins; 2.55-2.4 Ga). Subsequent collision of the Pilbara and Yilgarn Craton deformed the volcanic and sedimentary rocks, forming the Capricorn Orogen/Gascoyne Craton (2.0-1.6 Ga). The Paterson Province (1800-750 Ma) overlies these regions, and consists of strongly metamorphosed sedimentary and volcanic rocks and granites, overlain by weakly metamorphosed sedimentary rocks intruded by granite. The Northampton and Leeuwin Complexes (Pinjarra Orogen; 2000-650 Ma) are parts of a belt of high-grade metasedimentary and granitic rocks along the western side of the Yilgarn Craton. Similar processes took place elsewhere in Western Australia. In the north, the Halls Creek Province of strongly deformed and metamorphosed sedimentary and igneous rocks wraps around a less deformed buttress of thick shallow-water sediments of the Kimberley Basin (1800-670 Ma) that rest on unexposed basement. In the east, the Musgrave (1600-1000 Ma), Arunta (1880-350 Ma), and Granites ? Tanami Blocks consist of metasedimentary and meta-igneous rocks that became basement to younger basins such as the Birrindudu Basin (1800-200 Ma), and Amadeus and Officer (830-350 Ma) Basins. The pattern is similar elsewhere, with sags or rifts on and between cratons or orogens being filled with sedimentary and lesser amounts of volcanic rocks in the Bangemall region (1600-1100 Ma), Bonaparte and Ord Basins (580-20 Ma), Canning Basin (460-0 Ma), Carnarvon and Perth Basins (420-0 Ma), Eucla Basin (150-0 Ma), and Bremer Basin (~50 Ma). The Albany-Fraser Province (1300-1100 Ma) differs somewhat from this pattern, in that it was a zone of tectonic reworking and metamorphism of the Yilgarn Craton, accompanied by emplacement of large masses of mafic and felsic igneous rock. ANZLIC search words:
Spatial domain:
Geographic extent name: WESTERN AUSTRALIA - WA - State or Territory - Western Australia Geographic extent polygon: 112.5 -13.5, 129 -13.5, 129 -35.5, 112.5 -35.5, 112.5 -13.5, Note: The format for each Geographic extent name is: Name - Identifier - Category - Jurisdiction (as appropriate) See GEN Register
Data currencyBeginning date: 2008-11-27 Ending date: Not Known Dataset statusProgress: Complete Maintenance and update frequency: As required Access
Access constraints: Subject to terms and conditions outlined in license.txt file. Free Data DownloadData qualityLineage: Most data was sourced from the most recent published 250K scale geological maps from the Geological Survey of WA or Geoscience Australia. Where these maps were not current, available 100K geological maps or 500K regional compilation maps from GSWA and Geoscience Australia were used. Linework was generalised from the source maps for presentation at 1:1 million scale. Positional accuracy: This data has a nominal scale of 1:1,000,000. Positional accurracy of linework vaires between 200 and 1000m based on the scale and heritage of the source maps. Attribute accuracy: All polygons are fully attributed with geological unit name hierarchy according to the Australian Stratigraphic Index and feature level metadata according to the Geoscience Australia digital data dictionary. All linework is attributed with geological attributes (ie: geological boundary, fault, water boundary) and feature level metadata according to the Geoscience Australia digital data dictionary. A geoscientist visually inspected the finished dataset to ensure the attributes were accurate and the data were consistent spatially with current scientific information. Data Dictionary standard: Geoscience Australia, Data Dictionary for GIS Products, Version 2007.01 (http://www.ga.gov.au/standards/datadict.jsp). Logical Consistency: The Arc/Info coverage dataset has been built with no label errors or intersecting arcs. Data structure conforms to the Geoscience Australia standard for a geology dataset. QA tests were also carried out on these data for completeness, correct spatial representation, attribute accuracy, logical consistency and correctness, and where appropriate for compliance with Geoscience Australia's data dictionary. Data Dictionary standard: Geoscience Australia, Data Dictionary for GIS Products, Version 2007.01 (http://www.ga.gov.au/standards/datadict.jsp). Completeness: The geological information is complete within the bounding polygon. Systematic checks have been made of both unit and line information throughout the entire data set. Contact information
Metadata informationMetadata date: 2009-03-31 Additional metadataMetadata reference XHTML: http://www.ga.gov.au/meta/ANZCW0703012215.html Metadata reference XML: http://www.ga.gov.au/meta/ANZCW0703012215.xml . Authors:Stewart, A.J. Sweet, I.P. Needham, R.S. Raymond, O.L. Whitaker, A.J. Liu, S.F. Phillips, D. Retter, A.J. Connolly, D.P. Stewart, G. |
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