The first true instance of flat gold mineralisation or flats that we have encountered (in which the gold orebody or mineralisation is near horizontal and usually associated with vertical lodes), would probably be Wallaby, next to Granny Smith in WA, followed by Avoca’s (AVO’s) Higginsville Athena lodes and other “flats”. There are a number of theories as to why “flat” gold mineralisation can occur.

The most recent two instances since February 2007 are currently conceptual and depend on further drilling to establish the interpretation. However, they are WCP’s Whistler in the Montague Goldfield of WA and Mineral Deposits’ (MDL’s) Sabodala in eastern Senegal.

Both these two recent instances exhibit similarities to Avoca’s mineralisation at Higginsville, having a fairly distinct near vertical shear zone and very distinct contact, with near vertical lodes, and apparent flat gold mineralisation. The flat mineralisation appears to have the capability to penetrate across the shear zone and into the usually perceived barren footwall.

Another characteristic is that grades are often “high”. Although not clear in the section of Sabodala shown in Figure 1, intersections do include grades up to 117g/t over the usual 1m. In Avoca’s case, values are often ~30g/t or so.

Also in Avoca’s case visible gold is often easily recognisable, though not at Sabodala where despite the grade, it is contained in the pyrite within a haematite breccia in the higher grade samples that we saw.

Flat gold mineralisation is something that appears to be rarely looked for, but perhaps it should increasingly be a consideration.

Disclosure and Disclaimer : This article has been written by Keith Goode, the Managing Director of Eagle Research Advisory Pty Ltd, (ERA, an independent research company) who is an Authorised Representative with Taylor Collison Ltd, and with his associates, may hold interests in some of the stocks mentioned in this article. The opinions expressed in this article should not be taken as investment advice, but are based on observations by the author. The author does not warrant the accuracy or completeness of any information and is not liable for any loss or damage suffered through any reliance on its contents.

Figure 1. Flat Gold Mineralisation at Mineral Deposits’ Sabodala in Senegal