North Queensland geology 1:1 000 000 scale map

Brief description

This digital dataset is a compilation of the best digital geological map data available in September 1996, drawn mostly from Department of Mines and Energy Queensland (DME) and AGSO published 1:100k, 1:250k, 1:1mil and 1:2.5mil scale geological maps, supplemented by Cainozoic geology from AGSO/(Cape York Peninsula Land Use Strategy) CYPLUS regolith landform and coastal zone maps. The 45 different map units reflect logical age/lithology groupings selected to provide a compromise between readability in hardcopy at 1:1mil scale and a useful amount of information. Internal boundaries of units grouped together were eliminated but the identity of mapped units within each polygon has been added to info tables. The digital dataset was constructed as a basis for hardcopy map products - a 1:1mil scale geological map and a 1:3mil scale geological atlas to accompany AGSO Bulletin 240 - not as a digital product per se. Subsequently, in 2001, the dataset was upgraded to serve as part of a new 1:1mil scale outcrop geology map of Australia. This work comprised QA/QC of linework and attributes, and the addition of polygon constituent information.

Lineage

Maintenance and Update Frequency: asNeeded

Statement: The first phase of the construction of this dataset, undertaken during 1996 and 1997, involved its compilation from a number of separate datasets. Most of the data was derived from post-1970 mapping (much of it at 1:100k scale, especially in the geologically complex eastern part of the map) published as second edition 1:250k scale geological series and special 1:250k regional map sheets. First edition (mostly pre-1970) 1:250k geological series maps were used in the geologically less-complex parts of the map. Some boundaries were derived from the digital version of the 1975 1:2.5mil scale Queensland Geology map. Cainozoic map unit boundaries in Cape York Peninsula north of 16 S are derived from AGSO/CYPLUS regolith landform and coastal zone maps. Additional information was derived from the 1:1mil scale Carpentaria-Karumba basins map, in the south-west part of the map, and the 1:500k scale Igneous Rocks of North Queensland maps. The compilation process involved a degree of generalisation of data and the absorption of smaller polygons into adjacent polygons. The compilation of the original dataset saw the removal of faults into their own dataset and the grouping of geological units into broader age-rock "groupings". The second phase, undertaken in 2001, involved the reintegration of faults into the geological dataset and the re-attribution of the original geological unit information. The reintegration of fault data into the coverage worked on the assumption that the location of the faults was more accurate than the corresponding 'geological boundary' linework in the geology coverage as the linework was not coincident. The re-attribution of geological unit information was done systematically from the separate "ungrouped" datasets used in the original process. The attribute accuracy of these datasets was checked against the sources used to create them and an exact list of those sources is provided in the Additional Metadata section.