A small area located 45 km north-east of Leigh Creek, which covers the sites of numerous small historic diggings made by prospectors searching for copper and lead-zinc-silver mineralisation, is now being explored afresh for possible economic...
A small area located 45 km north-east of Leigh Creek, which covers the sites of numerous small historic diggings made by prospectors searching for copper and lead-zinc-silver mineralisation, is now being explored afresh for possible economic diapir-related occurrences of base metals and gold. Following a preliminary interpretation made of available airborne geophysical survey data, field evaluation was made of selected anomalies via geological mapping, rock chip sampling and portable XRF geochemical analysis of soil samples. Several of the old mines and prospects were visited to try to observe any controls on mineralisation. 21 rock chip samples were collected for assay, predominantly from mineralised quartz veins. The peak values returned were 43 ppb Au, 41.45 ppm Ag, 4.18% Cu, 33.94% Pb and 8.81% Zn. An orientation soil sampling line was run from north of the Oodnapanickan Hut lead occurrence southwards to Jack’s Camp Well. Later, grids of east-west soil sampling lines were laid out, along which a total of 476 samples were collected at 100 m intervals, and in one area at 50 m intervals, from a depth of 5 cm to 10 cm. A minus-2 mm size fraction sieved from each soil sample was analysed in situ for 26 elements by way of a handheld Innov-X XRF spectrometer. Several anomalies were identified for further work ( geochemical maps are presented herein for major pathfinder element data). During 2009, 1092 further soil samples were collected and analysed in the field by FPXRF as previously described, except that this time around the samples were taken at 100 m intervals on 200 m spaced north-south lines, apart from at the Eromulka South copper occurrence where the sampling was done at 50 m intervals on lines 100 m apart. Anomalous nickel and copper were noted on the Eromulka South grid, apparently associated with an interpreted fold hinge. Widespread zinc, with minor lead and arsenic anomalism, was recorded south of Appealinna Well. Other work carried out in 2008/2009, lately reported, was the acquisition and interpretation of Landsat and Quickbird satellite spectral data by consultant Earthscan Pty Ltd (the final report is included herein). The remote sensing data was computer enhanced to highlight probable structural features and mineral alteration zones on EL 3947. Alteration zones were interpreted to occur firstly within the lower Sturtian calstic units that are possibly associated with low angle thrust structures and have a quartzite hanging wall, and secondly within upper Marinoan carbonaceous shales, dolomites and limestones of the Wonoka Formation, where intense haematite - carbonate altered haloes are evident. The main exploration activity undertaken during 2010 was the acquisition of new detailed airborne magnetic and radiometric data on the subject area, flown as part of a major survey covering multiple licences now held by Panda Mining within the Adelaide Geosyncline. More than 1000 line km was surveyed over EL 3947 along north-south flight lines spaced 100 m apart, with a nominal 45 m ground clearance of the geophysical sensors. The new magnetic data was interpreted by consultant David Isles, who identified two likely pyrrhotite-bearing anticlinal fold axis anomalies in the Ulupa Siltstone and the Nuccaleena Formation respectively, possibly denoting former iron-rich hydrothermal fluids entrapped beneath ABC Range Quartzite cap rocks. These magnetic high features were later traversed on foot during June to September 2010, when brief field visits were made to ground truth selected aeromagnetic, radiometric and remote sensing anomalies, to try to identify their causes. Pervasive boxworks after sulphide, scattered small gossanous quartz veins and some pyritic black shale beds were noted, but all were discounted as being economically unimportant. Several historic copper, lead or gold workings were also visited, geologically mapped and rock chip sampled, but no development potential could be discerned for these. Reconnaissance loam heavy mineral sampling was performed over two interpreted discrete small dipolar aeromagnetic anomalies, but no kimberlite indicator minerals were found by subsequent laboratory heavy mineral analysis. During licence Years 4 and 5, no field work was done. Plans were made to acquire more surface sampling geochemical data using portable XRF analytical equipment, in places on the south-western end of the Mount Serle Anticline which had not yet been sampled, to follow-up previous regional PXRF data indications of likely zoned stratabound base metal mineralisation that has formed in carbonate rocks of the Wilpena Group. During licence Year 6 (2012-2013), on renewed EL 5188, Panda Mining conducted an exploratory drilling campaign on the Mount Serle aeromagnetic anomaly target which lies on both EL 5188 and the company's adjacent EL 4240 Castle Rock to the south, also part of the Copley Project. In the campaign as a whole, 4 RC holes were drilled for a total penetration of 700 m, and then one hole was continued by diamond drilling, during which 326 m of core was cut. Two of the holes were located on the subject EL 5188: SRC002 drilled to 116 m hole depth at an inclination of minus 75 degrees towards an azimuth of 325 degrees, and vertical diamond hole SDD001 taken to a total depth of 541 m from beneath the end of a 215 m long RC precollar. Laboratory assaying of selected drill cuttings and drill core samples did not reveal any significant mineralisation. Examination of the drill core from SDD001 revealed strong metasomatic albite-sericite-+/-silica-+/-sulphide alteration of the Ulupa Formation shales and siltstones, which have intervals of pervasive brittle deformation. This hole is located in the apex of an eastwards plunging syncline, the axis of which has a ~2 km long magnetic high. The cause of that anomaly was thought to be finely disseminated magnetite associated with silicification of the bedrock which is evident below 200 m depth in the SDD001 drill cuttings and core. 13 grab rock chip samples were collected of outcrops in the vicinity of the magnetic high and were assayed for a wide range of elements, along with 41 selected sample pieces of quartered drill core and 69 selected 1-metre intervals of drill cuttings. During licence year 7, Panda Mining resumed doing reconnaissance surface geochemical sampling within EL 5188 at various locations that it deemed prospective. 37 grab rock chip samples of outcrop were collected and were laboratory assayed for a suite of 36 trace elements. A few significant anomalies were detected. In June-July 2014, the licensee contracted Anhui Fuxin Geology and Mining Pty Ltd to conduct detailed gradient array time domain ground IP surveys on its Copley Project acreage, using 200 m x 40 m and 100 m x 20 m dipole spacings. Two of the areas surveyed were located in part on the subject EL 5188. Three elongate subsurface IP chargeability anomalies were defined in the south-western corner of the licence area, which appeared to be related to particular NNW-trending structural features. During licence year 8, in September 2015, Panda Mining drilled 2 vertical exploratory RC holes for 781 m to test two of the IP anomalies. A 67 m diamond cored tail was cut in hole DEP002 over the depth interval 300-367 m. The targeted anomalies were interpreted to lie within the fault-separated parallel fold hinge zones of a Tapley Hill Formation anticline and a Ulupa Siltstone syncline that are located on either side of the Mundy Fault. 68 selected 1-metre depth interval samples of drill cuttings or drill core were submitted for assaying. No significant copper mineralisation was intersected by the drilling. A zone of disseminated sulphide present over the RC-drilled Ulupa Siltstone section 120 m to 160 m in hole DEP002 was believed to be the source of one IP anomaly. The source of the IP anomaly being tested by hole DEP001 was not found. During licence Year 9, no work was done. Further interpretation of the 2015 drilling data indicated that the disseminated sulphides which were encountered in hole DEP002 clearly occupy the hinge zone of a syncline. It was resolved to continue exploration of structures adjacent to the Mundy Fault which may control the accumulation of base metal sulphide mineralisation. It was thought that the results of earlier work done by CRA Exploration in 1992 at Stones claim located just outside of the licence area may serve as a guide to likely deposit settings. During licence Year 10, no work was again done. A site visit was undertaken to monitor drill site rehabilitation. During licence Year 11, no work was done. The company is engaged in negotiations for a regional Joint Venture, with terms being agreed with a major mining company and is awaiting Board approval for execution.