Broken Hill Exploration Initiative (BHEI)

• Project description
• BHEI Deep Seismic Reflection Surveys
• Outcome
• Outputs
• Products
• Related links

Project Description

The Broken Hill Exploration Initiative (BHEI) is a collaborative project conducted under the auspices of the National Geoscience Agreement (NGA) and is being carried out jointly by Geoscience Australia, the New South Wales Department of Primary Industries (NSWDPI), and Primary Industries and Resources, South Australia (PIRSA). It commenced in 1994 with a view to securing the long term economic prosperity of Broken Hill and Port Pirie, both of which faced an uncertain future following industry predictions that the Broken Hill ore body would be exhausted within 10-12 years.

The BHEI is a multidisciplinary project, bringing together high-resolution potential field data with regional geology, petrophysics, petrology, geochronology, geochemistry, seismic and radiometric data, structural analysis, and metallogenesis studies to provide new insights into the geological evolution of the Broken Hill-Olary region, and thereby establishing a firmer and more effective basis for mineral exploration. BHEI work programs and geological research have been undertaken in both states, with the most recent field work involving Geoscience Australia being a joint project with PIRSA that aimed to better understand the structure and geological setting of mineralisation in the Olary Domain.

One result of the collaboration with PIRSA is a geological map of the Ameroo Hill area, within the Olary 1:100,000 mapsheet. An online version of the map and some of the datasets in the geological interpretation can be seen by following the links below.

• View the introductory notes
• Go straight to the Ameroo Hill GeoPDF (PDF, 1.4MB).
• View the detailed Ameroo Hill legend.

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BHEI Deep Seismic Reflection Surveys

In 1996-97 a consortium consisting of the New South Wales Department of Primary Industries - Mineral Resources, Geoscience Australia and the Australian Geodynamics Cooperative Research Centre acquired 294.6 km of explosive (dynamite) source deep seismic reflection data in the Curnamona Province in New South Wales from the South Australian border eastwards to the Darling Basin (Australian Geological Survey Organisation Record 1998/25). In 2003-04, another consortium consisting of Primary Industries and Resources South Australia (PIRSA), the Predictive Mineral Discovery Cooperative Research Centre (pmd*CRC) and Geoscience Australia acquired 198 km of vibroseis source deep seismic reflection data in the Curnamona province in South Australia from the New South Wales border to the Flinders Ranges (Geoscience Australia Record 2006/12).

In 2005, the New South Wales Department of Primary Industries - Mineral Resources and Geoscience Australia combined to acquire a high resolution deep seismic reflection profile approximately 12 km in length immediately to the east of Broken Hill. The energy source was vibroseis, and the new seismic profile followed the route taken by the 1996-97 Broken Hill deep seismic reflection profile 96AGS-BH1B, which was acquired using a dynamite source. The high resolution survey was designed to provide a high resolution seismic image of the uppermost part of the crust across an economically important area along strike from the world class Broken Hill Ag-Pb-Zn deposits using modern acquisition equipment and processing techniques. A brief outline of this survey can be found in Geoscience Australia Record 2006/21

Key results, products and conceptual advances pertaining to the Broken Hill and Olary Domains have already been released; products are available below, or through the Geoscience Australia Sales Centre.

Below: Distribution of Cu-Au and Pb-Ag-Zn mineralisation in southern part of the Curnamona Province. Much of this mineralisation is located at, or close to, the contact between two regionally extensive metasedimentary sequences, the lower, which is highly Na altered, is composed mainly of quartzofeldspathic rocks whereas the upper is dominated by psammopelitic compositions (after Skirrow & Ashley, 2000).

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Outcome

Enhanced exploration strategies for, and promotion of, the Curnamona province as an area of Cu-Au and Pb-Zn mineral potential through increased understanding of the regional structure and stratigraphy of the Olary sub-domain.

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Outputs

• Geological map and report documenting the structure, distribution, and stratigraphy of key rock units for part of the Olary Domain, including the heavily sulphidic Bimba Formation.
• Papers and presentations of BHEI results at conferences and seminars to promote and stimulate interest in the Curnamona Province as an area with further mineral potential.

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Products

GIS dataset

• Broken Hill: 250K scale GIS Dataset, 2006.
• Broken Hill - Curnamona Province regolith landform maps: 500K scale regional GIS Dataset, 1999.
• Broken Hill interpreted lithology: Regional GIS Dataset, 1999.
• Broken Hill geoscientific GIS dataset. Extended version, 1999.
• Broken Hill geoscientific GIS dataset. Standard version, 1997.

Airborne digital data

• Broken Hill NSW, 1994 (P617) - magnetic, radiometric and elevation point - located data.
• Broken Hill NSW, 1994 (P617) - magnetic, radiometric and elevation grids.
• Broken Hill (Regional), NSW, 1975 (P420).

Gravity digital data

• Broken Hill gravity digital data, 1:1M scale.
• Broken Hill - Menindee Point Located Gravity Data.

Geoscience Australia Records

Other publications

• Gibson, G. M., M. Peljo, and T. Chamberlain (2006): Reply to comment by Brian Stevens on "Evidence and timing of crustal extension versus shortening in the early tectonothermal evolution of a Proterozoic continental rift sequence at Broken Hill, Australia." Tectonics, 25, TC4010, doi:10.1029/2005TC001934.
• Gibson, G. M., Neumann, N., Southgate, P. N, & Hutton, L.J. (2005): Syn- and post-extensional orogenesis in the Palaeoproterozoic rift sequences of Broken Hill and Mt Isa, and implications for reconstructions of Rodinia. Supercontinents and Earth evolution Symposium, Abstracts Volume p.132. Freemantle, September 2005.
• Gibson, G. M. & Nutman, A. P. (2005): Reply to discussion by Conor et al. on "Detachment faulting and bimodal magmatism in the Palaeoproterozoic Willyama Supergroup, south-central Australia : keys to recognition of a multiply deformed Precambrian metamorphic core complex". Journal of the Geological Society of London, 162: 409-416.
• Gibson, G. M., M. Peljo, and T. Chamberlain (2004): Evidence and timing of crustal extension versus shortening in the early tectonothermal evolution of a Proterozoic continental rift sequence at Broken Hill, Australia. Tectonics, 23, TC5012, doi:10.1029/2003TC001552.
• Gibson, G. M. (2004): Testing reconstructions of Rodinia: new constraints from basement geology of Broken Hill, south-central Australia. 32nd International Geological Congress, Abstracts Volume, pt. 2, abstract 188-10, p.870.
• Gibson, G. M. & Nutman, A. P. (2004) : Detachment faulting and bimodal magmatism in the Palaeoproterozoic Willyama Supergroup, south-central Australia : keys to recognition of a multiply deformed Precambrian metamorphic core complex. Journal of the Geological Society of London, 161: 55-66.
• Page, R. W., Stevens, B. P. J., Conor, C. H. H., Preiss, W., Crooks, A., Robertson, R. S., Gibson, G. M., & Foudoulis, C. (2004): Relevance of new SHRIMP U-Pb ages to mineral exploration in the Cournamona Province. Geological Society of Australia Abstracts.
• Gibson, G. M. & Czarnota, K. (2003): Detachment faulting and shear-hosted mineralisation between upper and lower plates of contrasting tectonothermal history in the Palaeoproterozoic Willyama Supergroup, south-central Australia. Geological Society of Australia Abstracts.
• Gibson, G. M. (2002): Notes for a Broken Hill Exploration Initiative Field Workshop, In: Fabris, A. J. (compiler), Curnamona Province information package for Olary and Mingary Field workshop, October 2002. South Australia Department of Primary Industries and Resources, Mineral Exploration Data Package, 12, ch. 2: 20pp.
• Gibson, G. M., Crooks, A. & Szpunar. M. (2002): Structure of mineralised Palaeoproterozoic rocks in the Outalpa Inlier, South Australia. Geological Society of Australia Abstracts 67: 174.
• Page, R.W., Conor, C.H.H., Stevens, B.P.J., Gibson, G. M., Preiss, V. W., Southgate, P.N. (2005): Correlation of Olary and Broken Hill domains, Curnamona Province: possible relationship to Mount Isa and other North Australian Pb-Zn-Ag-bearing successions. Economic Geology. 100: 663-676.
• Page, R.W., Stevens, B.P.J., Gibson, G. M. (2005): Geochronology of the sequence hosting the Broken Hill Pb-Zn-Ag orebody, Australia. Economic Geology. 100: 633-661.

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Related links

• BHEI Key Results
• Ameroo Hill geology map introduction