North Pilbara synthesis GIS

Brief description

The North Pilbara project's main objective is to assist industry in their development off exploration strategies. In order to do this, we provide high-quality data sets such as this GIS, which provides different views of the same area, allowing correlation, comparison, and analysis at a broad scale across the entire North Pilbara. The advantage of this GIS is that it packages AGSO's primary data holdings for the entire region into a convenient digital package that can be manipulated and integrated with proprietary data in standard mapping applications. The North Pilbara GIS provides industry with a decision-making context, or wide-spaced framework. The lack of context is due the fact that industry commonly only have restricted data holdings over their leases. Therefore, regional synthesis data sets provide a context and framework for exploration decisions made on more spatially limited data. The North Pilbara GIS provides many new digital data sets, including a number of variations of the magnetics, gravity, and gamma-ray spectrometry. A solid geology map, and derivative maps, mineral deposits, geological events, and Landsat 5-TM provide additional views. This data set complements the 1:1.5 Million scale colour atlas (announced in June-July issue 58 of AusGeoNews). This provision of a regional digital data set will be an invaluable tool for exploration companies making comparative, correlative, and analytical decisions on the prospectivity of the North Pilbara. Just a few of the new aspects of the GIS include: -the under cover shape of prospective rocks with a new digital solid geology map; -all the images generated by the project (magnetics, gravity, Landsat, and radiometrics); -the imaging of several large shear zones, and complexity in granites; -compilation of geochemistry and geochronology; -a new chemical map based on radiometrics; -identification of the source regions of transported regolith

Lineage

Maintenance and Update Frequency: notPlanned

Statement: Geological mapping was compiled through integration of field mapping, aerial photograph interpretation, 400m line spaced airborne geophysics (magnetics and radiometrics), university studies and open file company reports. Mapping was scanned and digitised in Intergraph Microstation and Arc/Info from compilation sheets compiled on to topographic film bases. Digital map editing was performed using Arc/Info. Images were obtained from AGSO's corporate national datasets with specifications listed in the readme.txt file: Magnetics Digital Terrain Model Images Obtained from geophysical airborne surveys with 400 metre flight-line spacing, terrain clearance 80 m, AGSO Surveys P649, P651, P656. Gravity Images Gravity data is from a grid with 5 and 11 km spacing. Software used: Intrepid for data reduction and griding, and ERmapper for final grid display. Radiometrics Image Data from geophysical airborne surveys with 400 m flight-line spacing, terrain clearance 80 m, AGSO surveys P649, P651, P656. Software used: Intrepid for data reduction and griding, and ERmapper for grid manipulation and display. Original Radiometrics data was then equalised to give the best representation of the data.