Assays From First Hole Confirm Stunningly High-Grade Intersection In NSW
Sunrise Energy Metals (ASX:SRL/OTC:SREMF) has obtained significant drilling and assay results from the company’s platinum development activities at the Sunrise Project in NSW, Australia.
The first hole (SDD022) of a planned six-hole diamond core drill programme has returned an extraordinarily high-grade intersection of 0.6m at 129g/t platinum at 255.9m downhole. The intersection also includes significant grades of palladium, rhodium, iridium, osmium and ruthenium.
Co-Chairman, Robert Friedland, said the drill programme intersected structures (up to 390m below surface) with chromite sequences appearing between 125-260m (downhole) and, as expected, co-incident with the platinum mineralisation. The dunitic host structure is many kilometres in extent and is considered to be the source of much of the near-surface platinum mineralisation in the Sunrise laterite.
“We have long suspected that the Sunrise laterite may be the weathered surface expression of an Alaskan-style dunitic system that lies beneath – in the late 19th century this area was the world’s largest source of platinum and remains the site of the only primary platinum mine in Australia,” Mr Friedland said.
“Alaskan-style dunites host some of the major platinum occurrences in Russia and South Africa. Although it’s still early days for this new and exciting development, this stunningly high-grade platinum intercept is highly encouraging in terms of the potential for what may lie below this amazing Sunrise ore body. We will be following up this initial success with great enthusiasm.”
As well as testing the deeper areas below 200m, this initial hole was targeting an area of high-grade platinum mineralisation approximately 110m below surface which was identified in historic drilling undertaken by Ivanplats (SRC1257 returned 4m (from 119m) @ 7.4g/t platinum, 0.13% nickel and 0.01% cobalt, for 29.4 gram-metres platinum) 2.
SDD022 successfully intersected that target area, with visible indications of chromite veining. Multi-elemental analysis by ALS also indicates elevated levels of chromium, iron and magnesium.
Mr Friedland said Chromite veining is typically found coincident with platinum group elements (PGEs) in Alaskan style intrusive systems. Because of their magmatic origin and lack of hydrothermal alteration, these systems can be large and structurally contained.
Chromite veins were also reported by Ivanplats in the target area of SRC1257. Assay results from SDD022 in this area (including 0.3m (from 124.3m) @ 9.0g/t platinum) have confirmed historic data and provided important geochemical information to assist with broader modelling of the mineralisation at depth
Mr Friedland said the drilling results to date from the eastern flank of the dunite will refocus the remaining three holes of the planned initial drill programme on this side of the dunite to better understand the local platinum and PGE distribution, continuity and metal deportment.
Preliminary Metallurgical Analysis
Micro X-ray fluorescence analysis has been completed on one platinum intercept, with a further 11 still in various stages of progress, to further understand the platinum deportment and its relationship to other minerals within the host rock.
Within the tested sample the platinum and PGE’s occur coincidentally and interstitially, with grains up to 400um in diameter, adjacent to chromite grains or vein hosts suggesting a magmatic origin.
Platinum and PGE’s occur concentrically to the chromites which occur as disseminated grains, or veins of variable thickness.
Mr Friedland said the relatively large platinum and PGE grain size and their interstitial relationship with the chromite host is promising, as this suggests that the platinum and PGEs might be liberated and recovered by simple comminution of the host rock for further downstream metallurgical processing. Additional metallurgical studies are planned in order to further investigate this.
Additional samples are still being assessed and the results will enhance our understanding of the platinum genesis and deportment in these areas below the Sunrise laterite.