CCR Projects - Overview
Cobar Consolidated Resources Limited ("CCR") listed on the ASX in July 2006. Since then, CCR has been actively exploring an expanding tenement block which currently covers 1,837 sq km in the Cobar Mineral Field.
Figure 1: Location plan showing CCR tenements in relation to mineral deposits and simplified geology.
CCR Schedule of Tenements
CCR's tenements straddle the western margin of the Cobar Basin which is a geological subdivision of the Lachlan Fold Belt, a complex orogenic belt of lower to middle Palaeozonic age covering parts of NSW and Victoria (Figure 1).
The Cobar Basin is an asymmetric fault-bounded graben filled primarily with turbidites of Devonian age. The deepest part of the basin adjoins the eastern margin, which is a zone of strong faulting and moderate topographic relief (Figure 2). The three operating (and most of the historic) mines are located in this zone.
The western margin of the Cobar Basin is less well exposed and the only significant mineral discovery was relatively recent - the McKinnons gold mine which produced 127,000 oz of gold between 1995 and 2000.
A significant proportion of CCR's tenements are located to the west of the Cobar Basin, in rocks of the Winduck Shelf sequence, which is made up of sandstones, siltstones and lenticular bodies of limestone of similar age to the Cobar Basin. The boundary between the Winduck Shelf and the Cobar Basin is marked by major faulting and upthrust blocks of older Silurian granite, particularly in the southern part of the tenement block. The Booth limestone member of the Winduck sequence hosts the Wonawinta Ag-Pb-Zn deposit.
Figure 2: Schematic cross section through the Cobar Basin (Rohlach 2006). Approximate stratigraphic location of Gundaroo and Wonawinta prospects shown in red hatch.
Four distintc styles of mineralisation can be recognised in the area:
| ii | Sandstone-Hosted Ag-Pb-Zn | Stratiform-textured sphalerite-galena impregnation within the matrix of f-mg clean quartz sandstone/arkose. Examples include the CCR discoveries at Gundaroo (De Nardi and Ridge). |
| i | Cobar-Style Polymetallic Deposits | Steeply plunging pipe-like bodies of sulphides with varying proportions of Au-AG-Cu-Pb-Zn. The Peak, CSA and Endeavor deposits are typical of this type, which exhibit strong structural controls. |
| iii | Mississippi Valley-Type ("MVT") Pb-Zn-Ag | Stratabound but commonly discordant galena-sphalerite mineralisation hosted by dolomite or limestone; commonly occur as clusters of small (<10Mt) deposits in extensive districts. The primary Ag-Pb-Zn mineralisation at Wonawinta is generally considered to be of MVT type. |
| iv | Secondary and Supergene Deposits | Enrichments of base and precious metals in the near-surface weathered zone over marginal to sub-economic primary mineralisation of types (i) to (iii). Examples include Au (McKinnons and Goldwing), Ag (De Nardi and Wonawinta) and Pb-Zn (Wonawinta). |
Geological structure has a cricial control on all of the above deposit types. Fault structures appear to have acted as conduits for the basinal brines which have supplied the initial mineralising fluids and folding, shearing and fracture zones have influenced the deposition sites.
Figure 3 presents an overview of CCR's tenements showing the two resources (De Nardi and Goldwing) delineated to date, two areas where resource drilling is planned (Gundaroo Ridge and Wonawinta) and other prospects where geochemical sampling and drilling is at various stages. CCR's present focus is at Wonawinta, where the company is earning 70% interest from CBH Resources. The company has estimated target mineralisation of 20Moz of silver with base metal credits (approximately 50Moz Ag equivalent). A drilling program has been commenced to bring this mineralisation into the resource category. The similarities between the mineralisation located by CCR at Gundaroo and Wonawinta has led to the development of a vision - The Winduck Super Project. The company beleives that the area has the potential to host major resources of Ag-Pb-Zn in Winduck Group sediments proximal to major regional faults.
The Cobar Mineral Field is an attractive area for investment in mineral exploration and mining. It is characterised by high grade, log-life, multi-metal deposits, has good infrastructure, an experienced work force and a long-standing mining tradition. Mineral exploration and mining started in the Cobar Field in 1870 and continues today with three active mines producing gold, silver, copper, lead and zinc.
Figure 3: Prospect location and exploration status plan
