Regency Mines (LON:RGM) has released further details from Phase 1 of its reconnaissance air core drilling program on the Munglinup North Project in Western Australia. The air core drilling found traces of base and precious metals, and significantly it encountered an unexpected sulphide mineralisation (average grade of 10.06%) which may indicate potential for base and precious metal zones at depth.
The company completed the drilling of 2,401m over 51 holes in March, to test two anomalous target zones, T1 & T3. Air core drilling is used in areas of extensive cover, where it has the benefit of allowing geochemical exploration from near-surface down to bedrock, for indications of mineralisation at deeper levels.
Phase 1 air core drilling, was designed to conduct enough air core drilling to ascertain the underlying geology and reason for geophysical anomalies; as well as testing for covered greenstone occurrences that could indicate associated mineralisation.
The company said that plans for the Phase 2 drilling programme are underway. The second phase will include infill drilling to outline the structurally controlled sulphide zones, and deeper reverse circulation drilling to explore the source of the near surface base metal mineralisation.
At T1 (Target 1), Regency’s team tested an electromagnetic conductor at the interpreted boundary of the Archaean Yilgarn craton and the Proterozoic Albany Fraser Metamorphic Zone. The company noted that assay results showed traces of base and precious metals down to basement, however not at economic levels.
The southernmost drill line on T1 encountered the significant sulphide levels in all holes. The company emphasised that the sulphide intersections were not expected and they are potentially significant.
“The importance of the sulphide discovery at T1 is that the significant sulphide levels encountered may be an indicator of further sulphides along the south-western extension of the conductor, with potential for base and precious metal zones at depth,”, Regency stated.
The company revealed that the westernmost hole, of the southern line, MNAC2007, intersected 24 metres of sulphide at an average grade of 10.6%, with a maximum grade of 18% sulphide and ending in a sulphide mineralisation grade of 8.87%. For the same drill hole, Regency reported high levels of titanium, with an average grade of up to 2.24% Ti, and the mineralization in MNAC2007 is open in all directions.
The other intersects of interest include Ti, Pb, Cu, Zn, Co, Ag and traces of PGEs.
Regency acknowledged that the shallow depths tested by air core lie within the weathered zone where mineralization is potentially depleted and further drilling along strike and at depth will be carried out to test this hypothesis. Additionally, the company noted that ‘thin section analysis’ of the rock chips, collected from the drilling at T1, is also being undertaken to identify the sulphide source of this weathered material.
At the other target, the T3 magnetic anomaly, weathered ultra-mafics were encountered with anomalous Ni and PGE's from 2 holes. According to Regency, the result substantiates the hypothesis that the greenstone belt extends further south than previously thought. However, the levels of mineralization were insufficient to justify deeper drilling at T3, instead further and deeper drilling will be carried out at other targets along the belt, at a later stage.