Chamonix Zinc Prospect
Location
West coast of Tasmania. The Chamonix Zinc Prospect is located within the Linda Valley, due east of Queenstown within Corona’s 100% owned EL21/2010. The Linda Valley is a broad WNW-ESE trending glacial valley flanked by steep ridges of Mt Lyell to the north and Mt Owen to the south. The Mt Lyell copper mine is located due west of the prospect area on Philosophers Ridge at the head of the Linda Valley.
Minerals
Targeting zinc-lead metal mineralisation.
Geology
The Mt Lyell and Mt Owen ridges are part of basal Ordovician Owen Group conglomerates, while the valley floor is in part graben and in part synclinal structure with limited exposure of overlying Pioneer Sandstone and Gordon Limestone. Tight, smaller amplitude folding of the sandstone and limestone is apparent on Philosophers Ridge with possibly 3 synclines and anticlines plunging to the ESE, with reverse plunge to the WNW apparent 3km to the east.
Small exposures of Chamonix Shale (Corona terminology) have been recognised in the keels of the small synclines (mapped by previous workers as a decomposed limestone). This is a carbonaceous black shale unit with a carbonaceous sandstone basal section. The shale hosts small showings of zinc and lead mineralisation in Cemetery Creek and small gullies between that and Linda town site, 1km to the WNW in what is interpreted to be a single synclinal keel.
Pleistocene glacial moraine talus and recent creek alluvial cover large parts of the valley.
Mineralisation
Mineralisation seen to date within the “Chamonix Shale” appears to be sphalerite (Zn) rich with some pyrite and lesser galena (Pb) sometimes occurring as disseminations and semi-massive, associated with stratiform laminations or quartz veins. In Cemetery Creek, chip samples assaying to 21.1% Zn + 0.46% Pb + 35 g/t Ag have been obtained from the creek banks.
Previous Mineral Exploration
An area adjacent to Cemetery Creek was originally granted as “Zinc Reward Claim” in 1902 but the only evidence of this working is a small dump in a gully containing sphalerite and galena in association with a large quartz vein.
The only recent exploration dedicated to metals other than copper and gold appears to have been undertaken by Copper Mines of Tasmania Pty Ltd (CMT) who had just acquired the Mt Lyell Mine from RGC, starting in 1994, and who first recognised the high grade zinc mineralisation in the black shale in Cemetery Creek. They drilled two Reverse Circulation (RC) drill holes (94CZC001 & 002) beneath the outcrop and obtained intercepts of 13m @ 2.7% Zn and 12m @ 2.4% Zn just down dip in weathered black shale overlying fresh Gordon Limestone. Corona believes that there is potential for strata-bound, possibly syn-sedimentary zinc mineralisation in the Chamonix Shale unit.
Map
