East Iron Baron Special Declared Area
On Thursday 1 October 2015, the Minister for Mineral Resources and Energy published in the Government Gazette a Notice of Declaration of Exemption of Land (PDF)
The notice declares land within the Central Middleback Ranges to be a Special Declared Area (SDA) pursuant to section 9A of the Mining Act 1971 (Act). The SDA has been declared for a period of 2 years.
The SDA is east of Iron Baron, situated approximately 75 km southwest of Port Augusta, and covers an area of approximately 72 km2.
While the land is subject to the SDA, the Minister may call for applications for the grant of mining tenements over the area and determine the status and priority of any relevant applications.
On 10 December 2015 the Minister published a notice in the Government Gazette and on this website calling for applications over the SDA. The Department will utilise the standard exploration release area (ERA) process to ensure all interested parties have an opportunity to make an application over the area.
The area will be open for application from Monday 7 March 2016 – Friday 11 March 2016 inclusive.
This process will allow interested parties to undertake an assessment of the available data to consider their interest in the SDA.
The South Australian government has value-added to the release of the SDA by:
- releasing via open file all data from the SDA so that it is available to industry prior to calling for applications over the area; and
- providing additional information on geology, mineral potential and available geoscientific datasets.
Applications will be assessed via the standard merit based assessment process as outlined in Minerals Regulatory Guideline MG17 - Guidelines: applying for mineral exploration release areas (ERAs) in South Australia (PDF 1.3MB).
A preset map showing the SDA can be downloaded from the South Australian Resources Information Geoserver (SARIG) - Download the preset map showing the SDA
The envelope numbers (ENVs) contain links to download the exploration licence envelope pdf files. The envelopes contain information related to the exploration activity for each former exploration licence. Note that the pdf files may also contain drill-hole, sampling and other data, accessible via the ‘paper clip’ within the pdf.
|EL||Sub ELs||Licence holder||ENVs|
|266||–||BHP Company Ltd||2869 and 3154|
|398||–||Samedan of Australia Ltd||3292|
|537||–||Stockdale Prospecting Ltd||3643|
|965||–||Stockdale Prospecting Ltd||3643 and 5249|
|1193||–||Aberfoyle Exploration Pty Ltd||3643 and 5249|
|1581||–||Burmine Exploration Pty Ltd||8184|
|1735||–||Western Metals Copper Ltd||8520|
|1663||–||BHP Company Ltd||8338|
|2109||BHP Company Ltd||9167|
|2763||OneSteel Manufacturing Pty Limited||9167|
|3516||OneSteel Manufacturing Pty Limited||9167|
|2228||–||Equinox Resources Ltd||9276|
|2909||–||Equinox Resources Ltd||9276|
|3236||–||Resource and Capital Management SA Pty Ltd||11132 and 11208|
The SDA is located east of the Middleback Ranges in the vicinity of the Iron Baron/Iron Prince mine.
The area is located within the North-Western sector of the Moonta Subdomain of the Gawler Craton. The Moonta Subdomain is a region of three packages of Paleoproterozoic to Mesoproterozoic stratigraphic sequences consisting of metasediment, and metavolcanics and their associated igneous intrusives. These packages include the lower stratigraphic package of Paleoproterozoic Myola Volcanics (Tip Top Granite, ~1775Ma), and Broadview Schist (~1790Ma), overlain by younger, Mesoproterozoic Moonabie Range Beds and McGregor Volcanics (~1750Ma), in turn overlain by metasediment of the Wandearah Formation (~1720Ma). The whole has been affected by faulting, and folding of the Kimban Orogeny (1730–1690Ma), also the major mineralising event accompanying the Hiltaba Event (~1600–1590Ma), intrusion of NW-trending dolerite dykes of the Gairdner Dyke Swarm (827Ma), and re-activation of major N–S trending shears during the Tertiary.
Essentially the area of the SDA is located within an area of N–S trending major shears that appear to be part of a horsetail splay system being formed at the NE extension of the regionally significant dextral, transpressional Kalinjala Shear Zone. In particular the SDA area is located marginal to the major N–S trending (Moonabie)-Myola-Corunna Fault, and its offshoot, the Ash Reef Fault that together appear to control the distribution of the Myola Volcanics, and Broadview Schist. In the area of the SDA this fault separates Broadview Schist/Myola Volcanics to the east from Cooyerdoo Granite (~3150Ma) to the west.
Recent (unpublished) mapping by the Geological Survey of South Australia has determined the following geology.
Within the SDA outcrop is limited, with the surface geology dominated by Pleistocene sand plain deposits.
The basement stratigraphy comprises a sequence of Paleoproterozoic sediments, volcanics and intrusives.
The Myola Volcanics are a sequence of pink to grey porphyritic rhyolite interlayered with felsic and fine-grained quartz-feldspar-hornblende gneiss, and has a crystallisation age of ~1790 Ma.
The Broadview Schist is a sequence of fine-grained micaceous meta-sandstone, deposited after ~1795 Ma and contains basaltic to gabbroic intrusions. It is intruded by and interleaved with the Tip Top Granite, a medium to very coarse-grained quartz-potassium feldspar- plagioclase - muscovite ± tourmaline ± garnet granite with a crystallisation age of ~ 1775 Ma.
This Paleoproterozoic sequence underwent low temperature metamorphism during the Kimban Orogeny (1730–1690 Ma), and contain a tectonic foliation steeply dipping to the NE and SW, occasionally observed folded by tight folds. Prominent NW trending fault scarps traverse the release area.
Reprocessed gravity imagery confirms the presence of 2 distinct linear NNW-trending anomalies presumably sourced from Myola Volcanics/Broadview Schist. Aeromagnetic imagery confirms strong, cross-cutting NW-trending magnetic anomalies presumably sourced by dolerite dykes of the Gairdner Dyke Swarm.
Mineral potential of the SDA area includes the following:
- Base and precious metals
The area is located within a district considered prospective for IOCG-(U) type mineralisation, in particular shear-hosted deposit styles, more specifically at shear intersections. Past exploration in the immediate area has identified major NS-trending shears cut by NW-trending shears. Best example is the Moola prospect ~15 km south of the SDA. Ground reconnaissance by calcrete and soil geochemistry identified an association of anomalous Au-(Cu) with the interpreted shears. Drilling confirmed widespread, near-surface, low-grade Cu-(Au-Ag-Co) mineralisation. There is potential that these near-surface mineral occurrences may originate from re-mobilisation of metals from deep-seated IOCG type orebodies.
The SDA area being located within a major craton and in a district with known significant crustal shears is potentially prospective for diamond bearing kimberlitic intrusions.
Interest for diamonds in the district commenced in the early 1980s, when stream sediment sampling indicated a widespread distribution of ilmenite. Subsequently Stockdale Prospecting Ltd completed loam and stream sediment sampling in the mid 1980s (Envelopes 3643, 3492). The sampling included the area immediately north of the SDA. One grain of kimberlitic type garnet was confirmed. Ilmenite grains from alkali gabbros were probed and reported to be non-kimberlitic.
Stockdale Prospecting Ltd with farm-in partner Mobil Energy Minerals Australia in the early 1980s completed a program of mapping, and chemical analysis of loam samples for uranium in the search for vein-(breccia) style mineralisation associated with felsic intrusives (Envelope 3463).
The presence of the Iron Baron to Whyalla railway, which traverses the area of the SDA, might be considered a favourable factor in the development of resources of industrial minerals, and/or construction materials.
- Industrial minerals
Two large NW-trending quartz veins are mapped within the SDA, in particular a south-western occurrence that appears to be intruded along a major fault, with the fault line appearing to continue for some distance beyond the southern and northern boundaries of the SDA. Within the SDA, this fault line is marked along its strike by zones of vein quartz, breccia, and granite. Similar vein quartz is mined for silica at the 23 Mile Quartz deposits (mindep # 3015, 9451) 15 km to the north.
- Construction materials
BHP Pty Ltd held a series of extractive mining leases (EMLs) in the mid 1970s adjacent to the railway line, and over areas of subcropping weathered metasediment of the Broadview Schist, presumably as a possible source of ballast and road base material, though no production was ever recorded (see mindep # 10610–612).
For more information, contact:
Phone: +61 8 8463 3103