During the fifth year of the Curnamona Project, field activities were carried out only on Benagerie EL 3586, and consisted of the drilling of 2 inclined diamond cored holes for 424.3 mm (NPDD034 and NPDD035) at the North Portia prospect during...
During the fifth year of the Curnamona Project, field activities were carried out only on Benagerie EL 3586, and consisted of the drilling of 2 inclined diamond cored holes for 424.3 mm (NPDD034 and NPDD035) at the North Portia prospect during August 2008, to obtain core samples of the supergene Cu-Au ore for metallurgical tests required as part of ongoing studies into the feasibility of mining this Cu-Au-Mo deposit. Both holes intersected the Tertiary sequence, then the mineralised sequence of albitites and carbonates in the supergene zone, as planned, and were terminated in the magnetic footwall albitities. To check on the validity of suspiciously broad intervals of significant gold assays coming from within weathered basement in three of the diamond holes the had previously been drilled during 2007, re-assaying of the core of hole PTDD206 was commissioned at ALS Laboratories using the screen fire method, with barren flush material between samples, which were processed in reverse order, to minimise any possibility of contamination. Exactly the same intervals were sampled as previously for this hole. The results revealed that, apart from within the base of Tertiary gold horizon and one or two short intervals in the weathered basement, the content of gold is uniformly very low. This finding showed that the original drill core assay results for hole PTDD206, and by inference similarly spuriously affected gold results that had been obtained in holes PTDD207 to 208, were incorrect. During the sixth year of the Curnamona Project, field activities were carried out on newly issued Mineral Claim 3669 covering the North Portia prospect within EL 3586, and on EL 3503. On MC 3669, Havilah undertook the drilling of 24 inclined aircore holes (NPAC036 to 039, 041 to 053 & 055 to 062) and 3 RC holes (NPRC040, 051 & 054) as part of a resource delineation infill drilling campaign totalling 3201 m aimed at deter defining the supergene resource, to inform decision making about the feasibility of mining the deposit. On Telechie North EL 3503, a radon emanometry soil survey consisting of 277 readings taken at 40 m station intervals along 7 lines was conducted during February and June 2009. During the seventh year of the Curnamona Project, field activities were carried out on EL 3586 and on EL 3405. On Benagerie EL 3586, activities during 2010 were confined to the drilling of 12 inclined aircore holes for 1540.5 m at the Mount John Dam prospect, which is located on the western flank of the Mount John Dome. These holes were designed to test the âProspective Sequenceâ, or Bimba Horizon, along with a coincident gravity low and flanking magnetic high, for Kalkaroo or IOCG style copper-gold mineralisation. Although they successfully defined the source of the magnetic anomaly as being a north-south trending zone of potentially significant magnetite-biotite-amphibole veining and alteration, no significant associated mineralisation was intersected in the drillholes. Consequently, no further work is planned at this prospect. A second radon emanometry ground survey, again using an electrostatic method to determine the equivalent radon emanation from surface soils, was undertaken on Mundi Mundi EL 3405. Readings were collected at 497 stations spaced at 25 m intervals along 6 lines spaced generally 100 m apart. During the eighth year of the Curnamona Project, field activities comprising exploratory and appraisal drilling were carried out on ELs 4133, 4313, 4691 and 4782. [Note: in-field handheld spectrochemical semi-quantitative analyses of newly recovered drill samples using a Niton portable XRF instrument, and petrophysical measurements of the magnetic susceptibilities of the samples, began to be collected by Havilah on a routine basis at this time]. Activities on Benagerie EL 4782 consisted of the drilling at the Lorenzo prospect of 4 inclined RC holes for 672.5 m plus 10 inclined aircore holes for 939 m, to follow up a number of previous significant basement gold and copper-mineralised intercepts, and to determine if any Portia style, base-of-Tertiary gold mineralisation is present. Scattered weakly anomalous Au, Cu and Mo assay values were recorded from within the basement, and the presence of a thin Portia style base-of-Tertiary sand layer with fine visible gold was confirmed in a number of holes. On Chocolate Dam EL 4133, activities consisted of the drilling of one vertical, pre-collared diamond hole to 381.7 m, the construction of this hole involving 66 m of rotary mud, 108 m of RC and 273.7 m of HQ and NQ core drilling. The hole's objective was to test a small but intense magnetic anomaly and associated gravity anomaly, thought to be possibly sourced from either a diamond bearing kimberlite pipe, or else a Cu-Au bearing magnetic intrusive breccia or diatreme. This hole intersected a Tertiary cover sequence down to 58 m depth and Adelaidean sediments to 335.8 m, and drilling was ended in Willyaman basement rocks consisting of meta-siltstone and pelite, the target anomalies remaining unexplained. On Eurinilla EL 4313, 3 inclined RC holes for 546 m were drilled to follow up geochemically anomalous drilled intervals encountered at favourable structural trap and geophysical sites around the northern nose and north-eastern flank of the Eurinilla Dome. Two of the holes put in on the north-eastern flank of the dome intersected significant intervals of moderately anomalous Cu and scattered weakly anomalous Au values. On Mulyungarie EL 4691, 4 RC holes for 812 m were drilled to follow up geochemically anomalous drilled intervals encountered at favourable structural trap and geophysical sites around the south-eastern margin and southern nose of the Eurinilla Dome. Two of the holes on the eastern flank of the dome recorded intervals of moderate to highly anomalous Cu and Au downhole assay values, although sample quality was poor. During 2012, the ninth year of the Curnamona Project, separate exploration programmes were operated by Havilah and by new farminee MMG. Havilah's work was focussed on Mulyungarie EL 4691, where it drilled 3 RC holes for 459 m to continue to follow up previous significant basement gold and copper-mineralised intercepts and to test the âProspective Sequenceâ at favourable structural and geophysical sites around the south-eastern margin and southern nose of the Eurinilla Dome. Two of the holes were abandoned prematurely without reaching their targets, and did not intersect any significant mineralisation. The other hole, HMURC080, encountered strongly anomalous Au (up to 2.63 ppm), Cu (up to 4740 ppm) and As (up to 3000 ppm) at the base of the oxidised saprolite, while weakly anomalous Au (up to 0.20 ppm) and strongly anomalous Cu (up to 2390 ppm) was found to occur below the base of oxidation, and continues downwards into fresh basement rock. Anomalous Mo (up to 311 ppm) was detected in unoxidised saprolite. MMGâs 2012 exploration program commenced with the flying of a detailed, high resolution airborne magnetic survey covering the entire option area. 102,033 line km of aeromagnetic data were acquired at 50 m line spacing and an average sensor height of 30 m above the ground surface. MMG also acquired new ground gravity data from 6303 stations read across six tenements, to complement existing ground gravity datasets. Following on from this initial geophysical data acquisition and interpretation phase, MMG drilled 173 vertical aircore holes for a total penetration of 13,154 m, plus 1 diamond cored hole for 695.2 m, to test seven targets located on ELs 4691, 4782 and 4313. The aircore holes made several anomalous copper (up to 1%) and gold (> 1 ppm) intercepts at the Eurinilla Dam and Croziers Dam prospects, none of which were considered to be significant. At the former, the intercepts were interpreted to be related entirely to the equivalent of the regionally base metal anomalous âBimba Horizonâ, while at the latter, they were interpreted to probably be related to minor skarn-type mineralisation, which could be worthy of follow-up diamond drilling to gain further understanding. The sole diamond hole was drilled at the Imperial prospect on EL 4691, and was designed to target a faulted and structurally complex section of the western margin of the Mulyungarie Dome. At this location the geophysical data had suggested that a low density and possibly demagnetised zone was present at the intersection of two major fault structures, which might be favourable for copper mineralisation. However, the diamond drilling results revealed a locally relatively thick Adelaidean sequence overlying unmineralised basement. The geophysical features were thus interpreted to represent localised faulting (half-graben?) which has resulted in a relatively deep Adelaidean depocentre forming at this particular marginal location. MMG decided not to conduct further exploration at this prospect.