EL 28563 Bonney Well North, Final report, reporting period from 25 August 2011 to 10 July 2013

Abstract

EL 28563 Bonney Well North butts up to Cabbage gum bore field 10km south of Tennant Creek township extending east to Stuart Highway south to Edinburgh Creek and west to the NT Gas pipeline comprising 336sqkm. The licence area is considered prospective for IOCG deposits hosted by mineralised subsurface magnetic ironstones which have produced 155 tonnes Au, 400,000 tonnes Cu since 1950 in the Tennant Creek field 40km to the north. Prospectivity is confined to an arcuate array of AMAG anomalies notated B, C, D and E which occur around the inferred contact from west to east of the Explorer granite and interpreted Warramunga Formation (1862 - 1870Ma host to all known ironstone mineralisation discovered in the Tennant Creek goldfield). The licence area is dominated by Cabbage gum granite (1848Ma) to the north and 'Explorer' granite to south with a raft of Palaeoproterozoic metasediments wedged between the above quartz-monzonite to granodioritic intrusives. Pn-Flynn Subgroup siltstones/volcanics (1852Ma) crop out at two significant localities however Warramunga Formation does not, even though diagnostic lithologies were intersected in E42 Geopeko DDH 001 thus confirming the underlying presence of Warramunga Fm-Pw across most of the licence area possibly a continuation of Rover sub-basin commencing 40km west of the licence area hosting Rover 1 (6MT @ 5.6gms/t, Au) a mineralised ironstone-hosted, Tennant Creek field deposit analogue. AMAG anomalies B4 and C4 are deemed worthy of GMAG followup and subsequent drill testing. E3/E42 is a 1000 nanotesla dipolar anomaly however after 5 previous drillholes no significant mineralisation has been intersected even though (by an order of magnitude) its the most intense subsurface magnetic response within the licence area. Review of available located, digital aeromagnetic data implies prospective Warramunga Fm (182Ma) underlies Flynn Sub Group metavolcanics at somewhat prohibitive depths (>250m) rendering ongoing proposed drill testing unsustainable hence licence is surrendered.