No field work was done on the subject licence during its first year, while land access permissions were being organised with the required authorities. The licence area is located approximately 100 km south-west of Coober Pedy and lies within the...
No field work was done on the subject licence during its first year, while land access permissions were being organised with the required authorities. The licence area is located approximately 100 km south-west of Coober Pedy and lies within the Woomera Prohibited Area. It was taken out because Marmota Energy believes that the region has good potential for finding economic buried Archaean ‘Challenger’ style gold mineralisation, and because the Aurora Tank prospect covers a prominent magnetic anomaly caused by banded iron formation within the Christie Gneiss. A thorough program of calcrete sampling was undertaken over the Aurora Tank Prospect by previous explorers. The program defined a 2200 m long zone of anomalous gold along the eastern margin of a magnetic unit, trending at approximately 0300, with discrete peaks up to 59 ppb Au. A second zone on the NW side of the magnetic anomaly and trending at 0500 is 800 m long and peaks at 38 ppb Au. Minotaur Golds' RC fence-line drilling of anomalous gold-in-calcrete geochemical anomalies at this prospect during May 1999 successfully delineated primary Archaean Au-As mineralisation. Two drillholes intersected fresh mineralised gneiss, viz. RCAT-8 (4 m @ 0.6g/t Au) and RCAT-13 (4 m @ 1.6g/t Au). During licence Year 1, Marmota Energy compiled all previous exploration data for this part of the Christie Domain into its geological databases, and undertook a thorough assessment of the context of previously discovered gold mineralisation in order to gain a greater understanding for ongoing exploration targeting. EL 4433 is located in the Woomera Prohibited Area, and a Deed of Access is required prior to entering the tenement. The process to obtain a Deed of Access commenced in May 2010, and it was granted by the Department of Defence in early 2011. A field visit made in February 2011 was used to assess the suitability of previous surface geochemical sampling methods. ********** During licence Year 4, work now subject to the Apollo JV management control consisted of desktop studies and the compilation and modelling of available magnetic and gravity data, followed by field mapping, rock chip sampling and the acquisition of a detailed ground gravity survey. Rare areas of outcrop found in the southern part of the licence area during a reconnaissance field visit were rock chip sampled. One of the samples was dated at the University of Tasmania, in the CODES – ARC Centre of Excellence in Ore Deposits facility, using LA-ICP-MS methods to investigate the U(Th)-Pb isotope ratios present within individual zircon grains. This purple brown, ironstone rich quartz breccia or perhaps conglomerate?/pyroclastic? rock was age dated at 2501 Ma ±14 Ma. During December 2013, the ground gravity survey was acquired over a 35 square km area. It comprised 473 stations read along east-west lines spaced at 450 m x 150 m, closing into 197 stations read on a 150 m x 150 m infill grid. Results confirmed the presence of a buried dense body associated with a 6 km strike length magnetic anomaly. During licence Year 5, in March-April 2014, Southern Exploration acquired an offset dipole-dipole IP survey totalling 15 line km across four east-west arrays. Despite strong misgivings about the quality of the majority of resulting IP data, a number of chargeability anomalies were able to be identified which coincided with density anomalies seen in the ground gravity survey data. This work was followed in July 2014 by shallow RAB drilling on a 250 m x 250 m grid of 195 vertical holes with a total penetration of 1176 m, which geochemically sampled the bedrock-cover interface above the semi-coinciding magnetic and gravity anomalies. Further drilling in August 2014 of 2 inclined RC holes for 396 m to test geochemical and IP chargeability anomalies yielded an intercept of 4 m @ 5 g/t Au from 16 m depth in hole 14AT003, that included 1 m @ 15 g/t Au from 18 m. These holes penetrated intensely sheared mafic and granitic rocks showing evidence of multiple episodes of alteration resulting in development of chlorite, strong carbonate veining and sericitisation. A single petrological thin section sample of drill cuttings taken from the depth interval 161-162 m in hole 14ATRC001 was described regarding its lithology as quartz-feldspar-biotite schists with variations in grain size and foliation development. It was concluded that the protolith of this rock was a feldspathic metasediment. After the drilling, speculation arose that drill hole 14ATRC001 which had been drilled towards due west was not orientated optimally for intersecting the targeted geology and anomalism. Based on the low assay results obtained from it, and since sources of the IP and geochemical anomalies did not appear explained by geology, it was considered that this hole must have either tracked above or below the targets, with the miss suggesting that their sources are narrow, steeply dipping shears. During licence Year 6, in March-April 2015 on its recently renewed EL 5589, Southern Exploration drilled 35 angled RC holes for 1750 m, at 50 m hole spacing along three north-south traverses 250 m apart, to test rocks in the vicinity of the high grade gold intercept previously made in hole 14AT003, and also test for the causes of coherent surface calcrete geochemical anomalies and IP chargeability anomalies. 437 composited 1-metre drill cuttings samples were laboratory assayed for seven epigenetic gold system trace elements. Encouraging but lower tenor gold assay results were obtained in seven of the holes, the best result being 16 m @ 1 g/t Au from 20 m downhole, including 12 m @ 1.3 g/t Au. Consultant Dr Kevin Wills was engaged to review the Aurora Tank and Mars prospects and to provide advice as to each's prospectivity and possible future evaluation work. Dr Wills confirmed their joint prospectivity and identified four mineralised intersections worthy of further investigation by a suggested two-stage drilling campaign that should be performed over two 80 m x 40 m prospect grids. A first stage of RAB drilling entailing a combined total of 230 holes would aim to define the geometry of the secondary gold mineralisation in the saprolite, and would be followed by deeper RC drilling in a second stage, to target economic intersections of primary gold mineralisation.
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