LEAD-ZINC-SILVER ORE DEPOSITS HOSTED BY CAMBRIAN CARBONATES IN THE SOUTHERN KOOTENAY ARC, SOUTHEAST BRITISH COLUMBIA
The metamorphic grades are mainly lower amphibolite, increasing to kyanite and silimanite grade on Kootenay Lake. In the Salmo district, the grade decreases abruptly eastward across the Black Bluff fault. Orebodies and carbonates in the Metaline district of northern Washington State and east side of the Black Bluff fault in B. C. preserve original depositional and emplacement fabrics but most deposits in the Kootenay Arc to the west and north display isoclinal folding, and effects of regional and contact metamorphism.
Sulphides at the Bluebell are late fracture-controlled replacements emplaced as manto, vein, and pipe-shaped masses. The crystal-lined vugs and sulphide veins crossing stratigraphy and late structures at the Bluebell indicate emplacement after mid-Jurassic to earliest Cretaceous regional deformation and metamorphism. Major orebodies in the Reeves are tectonized and metamorphosed stratiform deposits in dolomite marble. They appear to record a syngenetic to early diagenetic phase of Paleozoic emplacement and subsequent epigenetic Jurassic to earliest Cretaceous phase. The MVT and oxide deposits in the Nelway and Metaline of the Salmo and Metaline districts were not subjected to the higher metamorphism and multi-phase folding that Cambrian deposits in the Reeves experienced but display features suggesting emplacement after regional deformation.