The Landrigan prospect is located where a BIF ridge is prominently displaced along an interpreted NW-SE fault. A number of locally ‘gossanous’ and malachite stained, silicified and talc-altered outcrops are present at the surface and initial interest was generated by an airborne electromagnetic anomaly.
It is defined by a single drillhole (EYD20) drilled by BHP in 1982 which was reported to intersect 9.6m at 2.7% Cu, 1.5% Zn, 0.3% Pb, 12.6 g/t Ag and 1.5 g/t Au associated with disseminated and minor semi-massive sulphides from 143.3 to 152.9m The interval from 176.7m to 177.05m returned 6.09% and 2.23% Mo and >0.5% Cu and Zn and 171 to 173.5m returned 0.81g/t Au and anomalous Cu-Zn. Follow up diamond drilling in 1983 by BHP failed to test the mineralised horizon; the positioning of holes may not have properly targeted the down-plunge extension of mineralization. Some near surface RAB holes returned 8m at 4.17% Cu, 1.04% Zn, 1.15% Pb, 16g/t Ag, and 0.11g/t Au, and 6m at 1.33% Zn, 0.43% Pb and 0.26% Cu.
Peako conducted Gradiant Array and Dipole-Dipole Induced Polarisation (IP) Surveys at the Landrigan prospect in late 2018.
At the Landrigan Prospect, GAIP and DDIP chargeability anomaly highs appear to be closely correlated with elevated Cu assays at the end of hole in historical RAB drilling, and a downhole intersection in diamond drillhole EYD020.
Separate GAIP chargeability anomaly trends located to the east and west of existing drillholes at Landrigan provide direct targets for drill testing to potentially expand the base metal mineralised zone, and to better understand the local geology and structural influences on base metal mineralisation at this prospect area, which do not appear to be well understood from historical exploration work to fit into a mineralisation style, such as VMS, sedimentary replacement, etc.
Interpretation of historical exploration work at the Landrigan Prospect projected the mineralised sulphide zone as a south dipping source for the bedrock Cu-Pb-Zn geochemical anomalism. However, the recent GAIP chargeability response from multiple receiver spacings, and a single DDIP survey line suggests a northerly dipping sulphide target source, which is untested by historical drill holes.
Peako has planned a number of drillholes to test the anomalous IP responses identified at the Landrigan Prospect.