Mount Isa Project
Geological remapping
In 2006, the GSQ commenced a programme of revising the geological mapping of the Mount Isa region. The revision was based on interpretation of the various geophysical datasets that have been acquired since the last phase of mapping was completed in the late 1970s, along with other remote sensing datasets such as Landsat and Aster images. The interpretation has been done in a GIS environment with digital versions of the previous mapping overlaid to highlight discrepancies and areas requiring follow-up field checking. In addition, results of detailed mapping by various universities, exploration companies and the Bureau of Mineral Resources (now Geoscience Australia) and the recently completed pmdCRC project were incorporated where appropriate.
Field work was done in four field seasons from 2006 to 2009. Final results of the mapping are currently being compiled with the aim of producing a seamless geological map of the entire region. In addition, geological boundaries and faults have been extrapolated under cover using the airborne magnetic data to produce a solid geological map. The seamless surface and solid geological mapping will be completed by June 2010.
In addition, the project aims to extend the interpretation of the solid geological interpretation under the cover of the surrounding Georgina, Eromanga and Carpentaria Basins using the newly acquired gravity and airborne magnetic data. Reinterpretation of the surface geology of these areas has been updated by interpretation of Landsat and airborne radiometric data.
A program of U-Pb zircon dating in conjunction with Geoscience Australia as part of a National Geoscience Agreement has been implemented. The samples dated include both igneous rocks to constrain the main magmatic events as well as detrital zircon studies to constrain depositional history and to facilitate correlations of the sequence stratigraphic packages across the region.
The resulting seamless surface and solid geology will be incorporated in a new version of the North-west Queensland Minerals and Energy Province Report and GIS due for completion in December 2010.
For more information contact:
Ian Withnall
Telephone +61 7 3362 9363
or Laurie Hutton
Telephone: +61 7 3362 9347
Since 2006 and 2007 there has been a major increase in acquisition of gravity and airborne geophysics data in the Mount Isa area by the Geological Survey of Queensland.
Survey A, over 25 976 km2 (6,566 stations), was completed in June and released in July 2006.
Survey B (B1 and B2), over 78 508 km2 (9898 stations), was completed in October and released in December 2006.
Survey C (C1 and C2), over 68 496 km2 (9043 stations) commenced in October 2006, and was completed on 2nd February and released in March 2007.
Surveys D and E, over 172 440 km2 (11 136 stations) commenced on 1st February and were completed on the 30th May, and released on 3rd July 2007.
Station intervals are 4kmx4km except for B1 and C1 which are 2kmx2km.
Released data are available for download from the National Gravity Database held by Geoscience Australia.
Isa airborne geophysics Project
Airborne geophysics has been acquired over the areas surrounding the exposed part of the Mount Isa Inlier to facilitate mapping of prospective units into areas of deep cover and encourage greenfields exploration in these areas. The data extends the coverage by open-range surveys done by Mount Isa Mines Ltd in the 1990s (and now in the public domain) as well as surveys done by Geoscience Australia in the Boulia-Springvale areas.
The Isa West survey to the west of Mount Isa collected 63 533 line kilometres of new magnetic and radiometric data over an area of approximately 21 937km2 . It was completed in April 2006 and released in August 2006.
The Isa South (W) survey collected 140 371 line kilometres of data over an area of approximately 49 936 km2. It was completed in August 2006 and was released on the 16th February 2007.
The Isa South (E) survey collected 100 972 line kilometres of data over an area of approximately 35 853km2. It was completed on the 12th November 2006 and was released on 4th April 2007.
The Isa East (N) and Isa East (S) surveys were completed on 15th July. The Isa East (N) survey, which collected 113 195 line kilometres over 39 897km2, was released on 9th October 2007. The Isa East (S) survey, which collected 113195 line kilometres over 51 373km2, was released on 27th November.
The Croydon survey, which collected 100 320 line kilometres over 35 206km2 , was released on 8th February 2008.
The Westmoreland survey, which collected 60 543 line kilometres over 20 911km2, was released on 13th May 2008.
All surveys are carried out at a line spacing of 400m and a ground clearance of 80m.
Released data are available from the GADDS system at Geoscience Australia, or on DVD from the Department of Mines and Energy on request.
For further information contact geophysics 07 3362 9357.
or the Geological Survey of Queensland
Block A 80 Meiers Road Indooroopilly Qld 4068
or the geological information hotline
+61 7 3006 4666 (9.00am to 4.00pm EST on working days)
or email the Geological Information Hotline
Last Updated 17 February 2010
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