Harris Greenstone Belt GIS Dataset

Brief description

The Harris Greenstone Domain (HGD) is a late Archean-Proterozoic arcuate tectnostratigraphic terrane in the centre of the Gawler Craton. It is bound to the south by the Yerda Shear Zone and has a lithological zone boundary to the north with the Wilgena Domain. The basement comprises Archean ultramafic-mafic extrusives (Lake Harris Komatiite), aluminous metasediments (Christie Gneiss), felsic extrusives and intrusives (Kenalla Gneiss), felsic intrusives (Glenroth Granite), and Proterozoic felsic intrusives (Hiltaba Suite Granite, St Peter Suite), felsic and mafic extrusives (Gawler Range Volcanics), and fluvial-marine sedimentary rocks (Tarcoola Formation, Pandurra Formation). The HGD is characterised by a series of sub-parallel east-northeast trending sinuous magnetic high features flanked by large ovoid to elongate magnetic highs and lows. The prominent narrow magnetic highs constitute the Archean Harris Greenstone Belt (HGB). Rock types in this poorly exposed belt include komatiite, komatiitic basalt, tholeiitic basalt, and subordinate banded iron formation, metasediments, felsic volcanics, and pyroclastics metamorphosed to amphibolite facies during the Sleafordian Orogeny at ~2440 Ma. The Lake Harris Komatiite, which represents the most eastern occurrence of komatiite in Australia, has potential for Ni-Cu-PGE sulphide and lode-Au mineralising systems. The prospective greenstone sequence is covered by thin (<50 m) Quaternary sand and Eocene fluvial channel deposits. The distribution and structure of the greenstones is based largely on interpretation of aeromagnetics, gravity, and diamond drillcore.

Lineage

Maintenance and Update Frequency: asNeeded

Statement: The geology dataset was compiled primarily from interpretation of airborne magnetic data and drill hole logging, along with gravity and minor AEM data. The magnetic data used for the interpretation was compiled by GA and PIRSA geophysicists from numerous regional government surveys and more detailed private company surveys. The vector data was digitised and compiled using ArcInfo 8.0.2. Geophysical and AEM images were exported as BIL files from ER Mapper 5.5. The BIL files were converted to geo-referenced TIF files in ArcInfo and then converted to a Mapserver compatible TIF via an Alchemy script.