PorterGeo
SEARCH  GO BACK  SUMMARY  REFERENCES
Great Australia

Queensland, Qld, Australia

Main commodities: Cu Au Co
Our International
Study Tour Series
The last tour was
OzGold 2019
Our Global Perspective
Series books include:
Click Here
Super Porphyry Cu and Au

Click Here
IOCG Deposits - 70 papers
All available as eBOOKS
Remaining HARD COPIES on
sale. No hard copy book more than  AUD $44.00 (incl. GST)
Big discount all books !!!


The small, high grade hypogene and supergene Great Australia Cu-Au-Co deposit is located ~1 km south of Cloncurry in the northern part of the 1900 to 1600 Ma Eastern Succession of the Mt Isa Block in Northwest Queensland, Australia.

For geological background on the setting, see the Cloncurry IOCG Province record.

Mineralisation occurs within a dilational jog in a major splay of the regional north-south trending Cloncurry Fault and is hosted by the Proterozoic Toole Creek Volcanics (greenschist facies basalt, andesite and interbedded meta sediments) of the Cover Sequence 3 Soldiers Cap Group and metasediments of the Cover Sequence 2 Corella Formation (dominated by bedded meta-carbonates and meta-siliciclastics altered to calc-silicate lithologies).

Both host units have been subjected to brittle deformation with breccia zones associated with NE-SW trending faults.   The hypogene mineralisation consists solely of chalcopyrite within brecciated fault veins grading up to 8% Cu, 1g/t Au, 0.35% Co in the two largest zones, the Main Lode and B Tangye Lode. Fluid inclusion data from euhedral intergrowths of dolomite and quartz suggest a formation temperature of 400 to 500°C, although secondary inclusions with low salinities indicate a later <200°C event (Cannell and Davidson, 1998).

The hypogene mineralisation consists solely of chalcopyrite within brecciated fault veins grading up to 8% Cu, 1g/t Au, 0.35% Co (Cannell and Davidson, 1998).

Supergene ores comprise surficial iron and copper cemented breccias, locally highly silicified, with deeper layers of malachite, azurite, chrysocolla, cuprite, native copper, atacamite, connellite and abundant copper phosphate.   Below and near the current water table, near the intersection of the two main hypogene sulphide lodes, a coarsely crystalline assemblage of chalcocite, djurleite occurs as a sulphide enriched zone.   Djurleite crystals up to 7 cm long with smaller, but well-crystallised chalcocite crystals, were cemented by multiple crystallisation calcite phases.   The deposit has been subjected to a long complex period of weathering and enrichment. All of the supergene events took place at <93°C.

The supergene leachable orebody contained 1.7 Mt @ 1.2% Cu in 1998.

For more detail consult the reference(s) listed below.

The most recent source geological information used to prepare this summary was dated: 2001.    
This description is a summary from published sources, the chief of which are listed below.
© Copyright Porter GeoConsultancy Pty Ltd.   Unauthorised copying, reproduction, storage or dissemination prohibited.


  References & Additional Information
   Selected References:
Melchiorre E B, Williams P A  2001 - Stable isotope characterization of the thermal profile and subsurface biological activity during oxidation of the Great Australia deposit, Cloncurry, Queensland, Australia: in    Econ. Geol.   v96 pp 1685-1693


Porter GeoConsultancy Pty Ltd (PorterGeo) provides access to this database at no charge.   It is largely based on scientific papers and reports in the public domain, and was current when the sources consulted were published.   While PorterGeo endeavour to ensure the information was accurate at the time of compilation and subsequent updating, PorterGeo takes no responsibility what-so-ever for inaccurate or out of date data, information or interpretations.

Top | Search Again | PGC Home | Terms & Conditions

PGC Logo
Porter GeoConsultancy Pty Ltd
 International Study Tours
     Tour photo albums
 Ore deposit database
 Conferences & publications
 Experience
PGC Publishing
 Our books  &  bookshop
     Iron oxide copper-gold series
     Super-porphyry series
     Porhyry & Hydrothermal Cu-Au
 Ore deposit literature
 
 Contact  
 What's new
 Site map
 FacebookLinkedin