Surface Geology of Australia 1:2.5 million scale dataset 2012 edition

Brief description

The 1:2.5M scale geology of Australia data documents the distribution and age of major stratigraphic, intrusive and medium to high-grade metamorphic rock units of onshore Australia. This edition contains the same spatial content as the previous edition, but its geological attribute data is more complete than the 2010 edition. The dataset was compiled to use at scales between 1:2.5 million and 1:5 million inclusive. The units distinguished/mapped mainly represent stratigraphic supergroups, regional intrusive associations and regional metamorphic complexes. Groupings of Precambrian units in the time-space diagram are generally separated by major time breaks; Phanerozoic units are grouped according to stratigraphic age i.e. System/Period. The time-space diagram has the added benefit that it provides a summary of units currently included on the themes. The method used to distinguish sedimentary and many volcanic units varies for each geological eon as follows: - Cainozoic units are morphological units which emphasise the relationship of the sedimentary fill to the landscape. - Mesozoic units are regionally extensive to continent-wide time-rock units which emphasise the System of Period(s). - Paleozoic units are stratotectonic units that emphasise either the dominant System or Period(s) or the range of Periods. - Proterozoic units are commonly regional stratotectonic units - separated by major time breaks and split into the Paleoproterozoic, Mesoproterozoic and Neoproterozoic Eras - which are generally unique to each cratonic region. - Archaean units are regional lithological units grouped into broad time divisions. Metamorphic units are lithological units which emphasise the metamorphic facies and timing of the last major metamorphic event.

Lineage

Maintenance and Update Frequency: asNeeded

Statement: The geological content of the 2012 edition of the 1:2.5M surface geology of Australia is the same as the previous 2010 edition (ANZLIC dataset ID = ANZCW0703013817), restructured to comply with 2012 Geoscience Australia and international data standards. The original data was compiled from digital data, mainly at 1:2 500 000 scale, supplied by AGSO, GSWA, NTGS, PIRSA, GSQ, GSTAS, GSNSW and GSVIC and from data obtained from many other groups. In order to synthesise data from a variety of sources into a coherent product, the degree and nature of modification of the source data varied from case to case. Cenozoic and Mesozoic units were derived from sources, including the Cenozoic Paleogeographic Atlas of Australia (Landford et al., 1995), the Geology of Australia 1986 and a compilation of Cenozoic basins in the Alice Springs region by B.R. Senior et al. (AGSO Record 1994/66). The Phanerozoic units of southeastern Australia are substantially a modification of the 1:2 500 000 scale map entitled "Stratotectonic and Structural Elements of the Tasman Fold Belt System". The geology of Tasmania is a generalisation of data assembled as part of the TASGO project (a GSTAS and AGSO/AGCRC venture completed in 1997). The geology of South Australia is a highly generalised modification of the 1993 1:2 000 000 scale Geological Map of South Australia. For the Precambrian compilation, much of the geology of Western Australia has been derived from the Geological Map of Western Australia, 1988 with some modifications. The geology of the Kimberley, Halls Creek, Tanami and Arunta regions has been updated in line with recent mapping and some input from magnetic interpretation to emphasise relationships with the Tanami region. The geology of the Amadeus region has been generalised from the 1:1 000 000 scale "Structural Map of the Amadeus Basin" (Compiler A.J. Stewart). The geology of the Musgrave region has been re-compiled and simplified. The geology of North Queensland has been generalised by D. Palfreyman and D. Pillinger from the "North Qld Geology, 1997" 1:1 000 000 scale map (compilers J.H.C. Bain & D. Haipola).