Friday, March 19, 2021

Xtract Resources – Bushranger – Hole 1 920m @0.3% Copper.

 

Xtract Resources– Bushranger – Hole 1 920m @0.3% Copper.

Well, we have the first assay results for Xtract Resources (XTR) on the Bushranger prospect in Australia.

Porphyries are not easily understood by the market and the response from XTR has unfortunately, not been the exception.

There is no doubt that Bushranger is a copper porphyry. What I mean by this is that this porphyry is dominated by the later, copper rich intrusions, which have overwritten the early barren or gold centric intrusions. There was much talk about mineralisation evidence of the kind of quick fluid cooling that leads to a gold rich, copper reduced porphyry. However, it is clear that this has been over-written by the later copper stages of intrusion action.

For simplicity sake, also for the cheaper capex, being just copper rather than a small copper and gold, is probably an advantage.

Moving onto the geology of the later section of the hole. We still find solid, if not spectacular copper grades. At first glance this might be concerning, we expect copper and gold to increase at depth. However, we know that the best mineralisation results are in the alteration zone next to the intrusion. Hole 1 was drilled to intersect this mineralisation, using the location of the intrusion from the existing JORC and to see if it continues. The problem is that a drill, operates in a straight line -near enough, therefore when the intrusion plunges or flatlines, as per fluid dynamics, it is impossible to remain in the sweet-mineralised area. Particularly if you are going to drill over 1km in length.

It looks like the mineralisation has travelled at a shallower dip from around the 500m mark, meaning that drill 1 passed through the outer mineralisation zone from about 500-600m to EOH. Hole 5 and 6 will be crucial in understanding this depth, particularly hole 6.

If we look more closely at the results, we can see that the top section 110m – 550m 400m is 0.42%. This is important, as any development or commercial decision of Bushranger, will be split. The common method of developing these systems in Australia, is to open pit down to the 500m level and then undertake targeted underground mining. With this known, the top section of mineralisation needs to be good, and 0.42% is more than good enough. A comparison to Rio Tinto’s Winu is useful here.

We know from an internal Anglo American Geology report, that more than a single porphyry exists at Bushranger. The below is a sample I’ve taken from that geology report that talks about Porphyry 2 at depth and in the outer northern edge of their Bushranger drill program in 2014-2015.

"Porphyry 2: Kspar+Plagioclase+Biotite-phyric Dacite Porphyry
This distinctive porphyry unit is present in TBRC030 @ 315.8m in contact with volcaniclastic
sandstone, and @329.6m, and@335.2m), in BRC032 @ 221.8m and @217.65 where it clearly
intrudes the monzonite), and in BRC034 (@ 169.3m, and @224.4m where it occurs in contact
with Porphyry 1). It also occurs in hole RACED020 where it is clearly intruding a volcaniclastic
siltstone.

This porphyry is distinctive in having large (to almost 1cm long) blocky Kspar phenocrysts that
often include one or more small plagioclase phenocrysts."

Given this and the alteration, porphyry mineralisation observed from as little as 50m depth in holes 5 and 6, we can assume that the second porphyry intrusion has an outer alteration zone that extends near to surface. Later assays will need to support this, but a safe assumption is that the second porphyry is also copper rich and will add to a potentially 1km east to west and 2km north to south open pit potential to 500m depth.

With this level of mineralisation, XTR should have no trouble increasing the JORC -after a planned infill program- to trigger the 2mt of Copper that requires Anglo American to buy 80% of the project. The company has talked about further IP surverys etc, but a second drill plan should complete a new, trigger JORC by the end of the year.

XTR has talked about finding new nearby porphyries that can attract an economy of scale in the same vein as the Cadia-Ridgeway grouping.

There is no doubt that further funding will be needed to complete the infill drilling and JORC creation of Bushranger to the 2mt mark. Whether that funding is created by the revenue streams of the African projects, via share issue or even by a partner coming on board for a cut of any sale price is largely immaterial for 2021.

So, to conclude; Bushranger this year will -very likely- become the second largest single copper deposit in the Lachlan Fold, behind Cadia East. The Rockley-Gulgong sub arc belt within the Lachlan Fold, was the sub belt that formed last in the geological history of the Fold, and as such, looks like the intrusions in the area will be predominantly copper rich. Just as Cadia is the gold work horse of the Fold, so the license areas held by XTR – which is the majority area of the Rockley-Gulgong volcanic area- looks to be the copper workhorse of the Fold. The unique characteristics of the sub belt leaves Bushranger and XTR in a unique position in a copper demanding world. If I can recognise that sat here thousands of miles away, I have no doubt that the copper experts in Australia do too!

Saturday, March 6, 2021

Xtract - Hole 5

 An estimated position, of hole 5. Given Sentinel Sat Information.