BROULA KING PROJECT
Mining Lease Application 225. The Broula King Project was the subject of an Environmental Impact Statement (EIS). An Environmental Impact Statement on the Broula King Project was lodged on 25 January 2005 and approved on 14 November 2005 which provides for the grant of Mining Lease 225.
Past Production and Recent Drill Exploration
Gold mining at Broula King is reported to have commenced in 1901 and to have continued intermittently until 1939. Available records indicate a past production of 2830 oz (88 kg) of gold.
Previous exploration has generated a large amount of data, much of it in the form of drilling and surface geochemical data over the mineralisation around the old Broula King workings.
In the period 1975 to 1976 Western Mining Corporation (WMC) drilled 45 percussion holes. In the period 1978 to 1982 Mines Exploration Pty Ltd (ME) drilled 3 diamond holes duplicating the WMC holes. During 1986 Cluff Resources Pacific Ltd (Cluff) drilled 6986m in 177 reverse circulation (RC) boreholes, extended 6 RC holes and drilled 517m of diamond drill holes.
Hardwon Resources took over the project in 2000, ultimately forming the Broula King Joint Venture (BKJV). The BKJV summarised the exploration drilling between 1975 to 1989 as 8,430m from 209 more holes. Many holes were drilled on a 10m grid and most were vertical.
Geology and Mineralisation
Regionally, Silurian age acid to intermediate volcanics, volcaniclastic sediments and limestones are bounded to the south by the Young Granite Batholith of Devonian age. To the north of this sequence are late Devonian sediments. The geology of the immediate Broula King area is generally described as consisting of four predominant rock types – dacite porphyry, tuff breccia, hydrothermal breccia and calcareous sediments.
The major controls on the mineralisation are a series of parallel quartz filled structures striking NNW and dipping steeply to the south-west. The quartz structures are truncated by a north-east striking fault – the Main (or Ridge) fault. This fault is near vertical, or steeply dipping to the north-west. Gold mineralisation appears also to be truncated by this fault.
The main host for gold mineralisation is the dacite porphyry. Here the gold is predominantly found as a low grade fine grained dissemination within highly altered (silica-sericite) zones.
Gold is also present in lesser quantities within quartz veins, near or along the vein margins and at a coarser grain size than the main mineralisation.
Disseminated pyrite is erratically distributed throughout the altered volcanics and seldom exceeds 2%. Galena and sphalerite occur in the thin quartz veins, with lesser chalcopyrite and pyrite.