2017 Exploration to Target Extensions to 302,000 Oz Gold Resource
- 2017 Aucu Gold Exploration underway - targeting increases to the high grade 302,000 Oz Deposit
- Bull dozer and field crew dispatched to Aucu Gold Project site
- Metallurgical test work and Mining optimisation study update
The field crew and a bulldozer have been dispatched to the project site to clear access tracks and to initially focus on developing drill tracks/pads at the Quartz Zone where drilling in 2016 identified 244,000 tonnes at 9.5 g/t gold containing 75,000 ounces of gold from surface to 100 metres depth.
The Quartz Zone appears to extend at least 200 metres further south east of the existing drilling. Outcropping mineralised shear zones occur in a track cutting 50 metres southeast of the existing drilling with channel sample assay results of 2 metres at 5.4 g/t and 1 metre at 0.7 g/t gold within sandstone. Quartz veins outcrop a further 100 metres southeast of the channel samples.
Bulldozer tracks currently extend 50 metres south east of the last Quartz Zone drill line and will be extended down the hill to cover the additional 200 metres of strike. The 2017 Phase one drill program will consist of approximately 1,200 metres Reverse Circulation drilling between, 70 and 130 metres deep, at the Quartz Zone. It is anticipated that drilling will commence as soon as sufficient drill pads have been constructed.
Subsequent drill programs will be conducted at the north western end of the Lower Gold Zone where drilling identified 6 metres at 38 g/t gold in LGZ15-29a. This target is hosted in a quartz vein having the same orientation as the Quartz Zone. The vein has been mapped along strike for 250 metres. Several bulldozer tracks and drill pads need to be completed prior to drilling and these will be constructed once the Quartz Zone dozer program is completed.
Also during the 2017 field season the Company is planning drilling to test extensions of the remaining resource zones (Sandstone, Upper Gold Zone, Camp Gold Zone and Eastern Gold Zone). Details of these drilling programs will be released later in the field season.
Metallurgical Test Work and Mining Optimisation Study Update
The Metallurgical test work being conducted by Bureau Veritas Minerals in Perth is nearing completion. The results will be reported once complete.
The Mining optimisation study being conducted by Mining Consultants Optiro Pty Ltd is currently underway. The study will establish how much of the existing shallow high grade gold resource could potentially be extracted via an open pit mining operation. This study will consider the relevant capital expenditure required to build an economic mining operation. The study results will be reported once complete.
Aucu Gold Deposit-Inferred Resource Summary
In April the Company reported an updated inferred resource reported in accordance with the JORC Code (2012) for the Aucu gold deposit (refer to ASX announcement 21 April 2017). The estimate above a cut-off grade of 1 g/t gold is:
1.8 million Tonnes grading 5.2 g/t gold, for 302,000 ounces of contained gold. The new resource represents a 93% increase in contained gold ounces and a 23% increase in average grade over the previous gold resource using the same cut-off grade reported in April 2015.
Importantly the new resource contains a new very high grade zone (Quartz Zone) of 244,000 tonnes at 9.5 g/t gold containing 75,000 ounces of gold, which starts at surface. Surface extensions of the high grade Quartz Zone have been identified and will be drilled in the coming field season.
This latest resource estimate also identified a new inferred copper resource reported in accordance with the JORC Code (2012), using a bottom cut of grade of 0.25% copper, of 608,000 tonnes at 0.64% copper, containing 3,870 tonnes of copper.
The new gold and copper resources start at surface, have only been drilled to 100 metres vertical depth and remain open along strike and at depth.
The reported gold resources represent less than 5% of mineralised faults identified by rock-chip sampling to date. Approximately 95% of the mineralised faults identified by rock chip sampling are still to be drilled. The gold bearing mineralised structures extend beyond the current resource estimate area over a length greater than 3,000 metres and occur as multiple lodes (see Figure 1 in the link below).
Resource Estimate: Aucu Gold Deposit
The new Inferred Mineral Resource for the Aucu gold deposit above a cut-off grade of 1 g/t gold consists of 1.8 Million tonnes grading 5.2 g/t gold for 302,000 ounces of contained gold. The new resource represents a 93% increase in contained gold and a 23% increase in average grade over the previously reported April 2015 inferred gold resource. Table 1 (see the link below) provides a breakdown of the updated resource estimate by area.
Importantly the new resource contains a very high grade zone (Quartz Zone) of 244,000 tonnes at 9.5 g/t gold containing 75,000 ounces of gold which starts at surface. Surface extensions of the Quartz Zone have been identified and will be drilled in the coming field season. Additional near surface high-grade gold resources are expected to be outlined from this program.
The estimate also identified a new inferred copper resource above a cut-off grade of 0.25% copper of 608,000 tonnes at 0.64% copper containing 3,870 tonnes of copper. This new copper resource is contained within the new gold resource areas and would be mined as part of an open pit gold mining operation.
The project also contains an inferred resource for the Chanach copper deposit which consists of 10 Million tonnes grading 0.41% copper for 41,000 tonnes of contained copper (above a cut-off grade of 0.25% copper), unchanged from 2015 (see Table 2 in the link below).
Summary of all information material to understanding the reported estimate:
The reader is referred to Appendix 1 (see the link below) of this announcement for detailed information regarding the resource estimate. The following is a summary of all material information to understanding the reported estimate.
The reported Aucu inferred gold and copper resource occurs in quartz veining and faults 1-10 metres wide within sandstone and porphyries. The sandstones dip at -20 degrees to the NNE and the porphyry intrusions are sub-vertical in several orientations. The quartz veins and fault zones are orientated NW to NNW are sub-vertical and cross all lithology's indicating that they formed after the sandstone deposition and after the main porphyry intrusion. The mineralised faults and veins cover an extensive area of over 5km2 and less than 5% of the identified faults have been drilled. The reported Chanach inferred copper resource occurs entirely within the main porphyry intrusion as several ENE to easterly trending shear zones that are sub-vertical (see Figure 1 in the link below).
The inferred mineral resource drilling has been conducted with a Korean Hanjin tracked reverse circulation rig drilling 130mm diameter holes using a pneumatic hammer and face sampling bit. This technique shatters the rock into small sub 10mm chips which flow into the centre of the drill rod and are transported to surface using high pressure air. The sample is collected in a cyclone before passing into a sample bag. Diamond Drilling has also be conducted using the same drill rig configured for collection of NQ (50mm) rock core.
Sampling is conducted on 1 metre drill chip samples where the 30kg sample is split using a three tier riffle splitter that reduces the sample to 3 kg for laboratory analysis. The remnant sample is stored for metallurgical test work if required. The entire resource is currently classified as inferred pending a site visit by the Competent Person to confirm laboratory quality assurance methods, sampling methods, geology, bulk density, drill hole locations, elevations and access. It is expected that some of the deposit will be reclassified as an indicated resource category when the site visit is completed.
Drilling has been conducted on 50m spaced lines with 25 spaced drill holes at the Aucu gold deposit. Drilling has been conducted on 100 metre spaced lines with 50 spaced drill holes at the Chanach copper deposit.
The resource has been estimated using Ordinary Kriging within ore wireframes using a minimum grade of 0.3 g/t for gold and 0.25% for copper. Up to 2 metres of internal dilution has been allowed for at zero grades. This updated Joint Ore Reserve Committee (JORC) 2012 compliant inferred mineral resource estimate was calculated by Perth based mining industry consultants Optiro Pty Ltd.
At the laboratory the 3kg drill sample is dried, crushed to 90% passing a 1mm screen then subsampled via jones riffle splitter to 300 grams. The 300 gram sample is milled to 90% passing 75 microns (0.075mm). A 30 gram subsample is weighed and analysed for gold via either an acid digest (aqua regia) with Atomic Absorption Spectroscopy (AAS) or via Fire Assay and AAS analysis. Copper and base metals are assayed using a 2-10 gram sample four acid digest followed by Inductively coupled plasma mass spectrometry (ICP-MS).
The resources have been estimated using a cut-off grade of 1 g/t (gold) and 0.25% (copper) based on likely mining scenarios. High grades have been reduced (Top Cut) to a maximum level via statistical analysis of the grade distribution of the metal in each domain.
Extensive metallurgical test work has been conducted on all mineralised zones. The test work includes total recoverable gold, gravity recoverable gold, cyanide recoverable gold, sequential copper leach and bottle leach.
To view tables and figures, please visit:
About White Cliff Minerals Ltd
White Cliff Minerals Ltd is a Gold, Copper, Cobalt, Nickel resources and mining company listed in Australia (ASX:WCN). The Company is focused on developing low cost high value mineral deposits that have near term cash flow potential.
Major projects include the Aucu gold deposit that contains 484,000 ounces of gold (3mt at 5.1 g/t) starting at surface and Chanach copper deposit that contains 64,000 tonnes of copper (17.2Mt at 0.37% copper). Both projects have substantial blue sky potential with drilling covering only 5% of the known structures. In Australia the company is developing the Coronation Dam cobalt–nickel deposit where a maiden resource will be announced in the late 2018.
White Cliff Minerals Ltd