An area centred located approximately 80 km west of Broken Hill and 19 km north-west of Cockburn is being explored for possible buried economic Broken Hill type stratiform Pb-Ag-Zn mineralisation. The tenement is also prospective for Kalkaroo or...
An area centred located approximately 80 km west of Broken Hill and 19 km north-west of Cockburn is being explored for possible buried economic Broken Hill type stratiform Pb-Ag-Zn mineralisation. The tenement is also prospective for Kalkaroo or Portia style epithermal copper-gold mineralisation which may also have formed within Palaeoproterozoic high grade metasediments. At previous explorer Aberfoyle Resources' Catch Dam prospect, historical RAB drillhole data indicate that anomalous zinc is present in covered bedrock within a low intensity magnetic zone now interpreted by Minotaur to represent Broken Hill Group strata, which are known to host mineralisation. Regional gravity data also reveal a small gravity anomaly high which is coincident with the above magnetic zone. These factors are considered to warrant further investigation through the conduct of higher resolution magnetic, gravity and TEM surveys, planning for which is in train. During the second licence year, no field or survey work was undertaken, activities instead being restricted to office-based prospectivity studies and the further review of past exploration data. A second voluntary partial relinquishment of 20 square km of ground was decided upon, to take place at the licence anniversary. During the third licence year, a small ground gravity survey was acquired at the Catch Dam prospect during August 2012 to improve the resolution of the existing gravity data, which vaguely showed a 1vd gravity anomaly defined by only two gravity stations. 204 new gravity stations were read at 200 m x 400 m spacing, and they dramatically improved the basement density definition, resolving linear and discrete gravity anomalies that could now be related to known basement lithologies such as amphibolite, calc-silicate rock and garnet-bearing mafic gneiss. An IP survey of three disparate length lines totalling 5.75 line km that was later conducted over the newfound gravity anomalies revealed several IP chargeability anomalies closely related to linear gravity anomalies, with one anomaly having an associated conductivity anomaly. Two IP chargeability anomalies on line 476250E and one IP chargeability anomaly on line 477850E were recommended for drill testing. Six basement rock chip samples taken from Catch Dam for trace element assaying revealed anomalous geochemistry from pelitic gneiss, calc-silicate rock and gossanous ironstone. The geochemically anomalous pelitic gneiss sample is spatially associated with the linear gravity feature that has the IP chargeability/conductivity anomaly on its northern flank. The association of this anomalous rock chip sample with IP and gravity anomalies was seen as further enhancing the prospectivity of the prospect. Drill testing of the IP anomaly was strongly recommended. During the fourth licence year, Minotaur's inversion modelling of the detailed gravity data collected in 2012 resolved several additional interesting gravity anomalies in the Catch Dam region. Follow-up IP surveying undertaken along three traverses over these gravity anomalies identifed significant IP chargeability anomalies that were recommended for drill testing, with priority given to four targets that were mapped at the following prospects; Bella Vista, Corsair, Cavalier and Sierra. Partial leach soil geochemical sampling was done at each of the 50 m - spaced IP stations (124 samples collected), but the results were fairly muted. Aboriginal heritage ground clearance surveys were conducted during May 2013 over chosen drill sites at the four prospects. During the fifth licence year, because of company budget constraints, Minotaur only completed drilling of a single exploratory hole, that was put in on the Bella Vista prospect. Inclined diamond hole 14DDCT001 was drilled to a hole TD of 450 m (with a 60 m RC precollar) during April-May 2014 to test a significant IP chargeability (i.e. 72 mrad maximum, 40 mrad anomaly) and conductivity anomaly on IP line 476250. It encountered a sequence of pelitic gneiss containing a thick interval of interlayered calc-silicate and psammite, this having low grade zinc mineralisation in the form of quartz veins with sphalerite-pyrrhotite-chalcopyrite, plus associated disseminated sphalerite. The mineralisation observed was not considered sufficient in amount to explain the IP conductivity anomaly, however, two zones of measured moderate conductivity in the drill core between 319–326 m and 352–358 m were considered sufficiently conductive to explain the anomaly. Drill testing of the remaining IP anomalies was still recommended, since these anomalies are not associated with gravity highs like Bella Vista is, thus indicating that these anomalies are not associated with calc-silicate but with other, different host rock types, and are potentially related to disseminated mineralisation.
More +