Pacifico Minerals Limited (ASX: PMY) has announced the completion of the Phase II drilling program at its Sorby Hills project in Western Australia.
The phase II infill and extension drilling program consisted of 75 drill holes for 5,959m, with assay results expected to flow from early August.
The company reported that the distribution of strong visible lead mineralisation indicates Phase II drilling program should increase Indicated Resources within the MRE.
PMY said that the northern section of CDEF deposit is expected to convert to Indicated for inclusion in the upcoming optimised PFS.
The company also reported that the observed zinc mineralisation in recent drilling confirms significant potential for future zinc production.
Sorby Hills JV project
The Sorby Hills Joint Venture project is located 50km northeast of Kununurra in Western Australia and consists of five mining leases totaling 4,157ha.
Pacifico owns 75% of the project while the 25% contribution is Henan Yuguang Gold Lead Co. Ltd, China’s largest lead smelting enterprise and the largest silver producer in China.
Phase I drilling increased IR
Pacifico had carried out a Phase I drill program in late 2018, that significantly increased the Indicated resources included in the Pre-Feasibility Study (PFS) completed in 1H 2019.
The PFS estimated a CAPEX of A$95.4M to develop the mine, with a 16-month payback and a pre-tax NPV of A$243M.
The Phase I drill program was designed to provide angled and oriented diamond drill core into B, C, CD link, D, F, and I deposits.
Results from the Phase I drilling campaign and assays from early 2019 had confirmed continuity between C, DE and F Deposits which is now considered as a single deposit (CDEF) with a strike length of 1.7km that may be minable with a single open cut.
It may be noted that the northern section of the CDEF deposit was excluded by Pacifico’s conservative approach from the March PFS as it did not include Indicated Resources.
Objectives of phase II drilling at Sorby Hills
Pacifico reported that it had commenced the Phase II infill and extension drilling program in May 2019 with an intention to combine an updated Mineral Resource Estimate (MRE) with the recently improved metallurgical testwork results and mining studies that are currently underway.
The company said that this was done to enhance the economics and improve confidence of an Optimised PFS scheduled for completion during Q4 2019.
The company reported that the drilling program was designed to convert Inferred Resources to Indicated Resources, currently at 10.9Mt of 5.0% Pb equivalent (3.9% Pb and 46g/t Ag); provide geotechnical information for pit designs; and to deliver representative samples for further metallurgical work.
Pacifico said that the program was focused on shallow mineralisation above 100m depth that may be mineable by open pit, at B and CDEF deposits.
75 holes for Phase II drilling
The company announced that the phase II drilling consisted of 30 reverse circulation (RC) holes, including ten as pre-collars to diamond drilled tails, and 45 HQ diamond holes for a combined total of 5,959m (inclusive of 427m mud rotary).
The majority of holes were inclined at 60° and drilled towards the west (azimuth 270°).
Phase II drilling: visual observations
Pacifico said that most of the core and all the RC samples have now been logged.
The company noted that the visual assessment of lead mineralisation indicates that significant intersections have been obtained. As well as expected galena (lead sulphide) in mineralised intersections, significant amounts of sphalerite (zinc sulphide) were observed in the drill core.
Possibility of conversion to Indicated Resources at CDEF deposit
The company reported the logging of abundant coarse galena through many of the Phase II program drill holes in the northern section of CDEF deposit.
The company said that with the analysis of the 12 drill holes with significant intersections at the northern part of the CDEF deposit combined with the 2019 drill program infill results, it is expected that a significant portion of the current Inferred Resource at the northern part of the CDEF deposit may be convertible to Indicated Resource.
Potential for future zinc production
The company reported that Zinc mineralisation was commonly observed during the Phase II program. There is an existing known Inferred Resource of zinc dominant mineralisation at the Alpha Zinc Deposit (2.34Mt of 0.5% Pb, 3.1% Zn, 29g/t Ag Inferred Resource).
The Company’s technical team noted that it sees great potential for the delineation of further zinc resources to add significant value and enhance Project economics.
The company reported that in parallel with advancing its mining studies, it plans to conduct further drilling in 2020 to continue expanding the Indicated Resource of the B and CDEF deposits, and convert Inferred Resources at the A, H, I, Alpha and Beta deposits to Indicated Resources.
The company said that other drilling targets include extensions to the zinc dominant mineralisation at the Alpha Zinc Deposit and targets outside the defined deposits for both lead and zinc.
Pacifico said that it expects the deposit size at Sorby Hills to continue to grow as extensions and other targets outside of the main defined deposits are drilled and added to the resource base.
The company reported that the compilation and assessment of the current and historical drill hole information are in progress, with an aim to provide a sound geological and mineralisation model on which to base the revised MRE.
The company said that the final assay results are expected by late August, and a revised MRE will be completed in September.