LETTERS TO THE EDITOR — Validating Flag’s claims

Flag Resources reported (T.N.M., June 15/92) that analyses from the first 1,500 ft. of core from its hole indicated enrichment in elements found in Sudbury ores. Flag specifically referred to the nickel and cobalt concentrations it has detected within a large pyritic, albitized quartz breccia and microbreccia zone in Huronian sediments overlying the Wanapitei anomaly.

Surface and diamond drill core samples from this zone are significantly anomalous in nickel, cobalt and gold, and variously anomalous in copper, platinum and palladium, all of which are commercially exploited in Sudbury area mines. All of these elements are also variously enriched in other mineral occurrences on the Flag property.

Neil Willoughby in his letter to the editor (T.N.M., June 29/92) implies that Flag’s report of extensive albitization in its drill core is the sole indication of “Sudbury-type nickel-copper-platinum group metals mineralization.” However, Flag clearly states that it is the afore-mentioned element concentrations together with the albitization that are associated with Sudbury ores.

Willoughby also implies that Flag has incorrectly interpreted the potential source of its Ni-Co-Au-Cu-Pt-Pd metal enrichment. He suggests that these elements are more likely related to the emplacement of the Nipissing Intrusions.

Minor albitization is recognized in the contact zones of some Nipissing Intrusions as Willoughby has pointed out. However, the albitized breccia zones recognized on the Flag property, and elsewhere in the Sudbury area, are distinct from these Nipissing-related alteration zones. They are typically encountered along large regional conjugate structures that post-date emplacement of the Nipissing Intrusions. This is clearly demonstrated by an albitized breccia hosting the “Camp Site gold-copper zone” on the Flag property and located one kilometre from the convergent albitized breccia Flag is currently drilling.

One of the few correct statements in Mr. Willoughby’s letter is that Ni-Cu-PGE elements are sometimes associated with Nipissing Intrusions (D.G. Innes and A.C. Colvine, OGS Miscellaneous Paper No. 90, 1979). However, his use of the Rathbun Lake occurrence on the Flag property may not be the best example. F.R. Rowell, in his 1984 M.Sc. thesis research of the occurrence, demonstrated that the mineralization is discordant and associated with hydrothermal sericite and chlorite that replace the primary mineral assemblage of the intrusion.

The source of the regional albitization of Huronian rocks in the Sudbury area has yet to be determined, as is the source of the Wanapitei magnetic and gravity anomaly. The enrichment of Ni, Cu, Co, Au, Pt and Pd in various albite alteration zones on the Flag property cannot be explained from a Huronian sedimentary source.

These elements are more typically associated with mafic to ultramafic igneous intrusions. The only known significant mafic intrusions in the area of the Flag claims are Nipissing although these clearly pre-date the alteration zones. A different mafic to ultramafic source must, therefore, exist in the vicinity of the Wanapitei anomaly beneath the sedimentary cover.

Robin Goad,

Vice-President of Exploration

Fortune Minerals Ltd.

London, Ont.