Vectoring Using Sulfidic Black Shales in the Vicinity of the Archean Kidd Creek Volcanogenic Massive Sulfide Mine, Ontario John B Chapman, Jan M Peter Geological Survey of Canada, 601 Booth Street, Ottawa, Ontario K1A 0E8, Canada Daniel Layton-Matthews Department of Geological Sciences and Geological Engineering, Queenʼs University, Kingston, Ontario K7L 3N6, Canada J Bruce Gemmell ARC Centre of Excellence in Ore Deposits, University of Tasmania, Hobart Campus, Private Bag 126, Hobart, Tasmania 7001, Australia Abstract. Graphitic, argillaceous and sulfidic (pyrite>>pyrrhotite-bearing) sedimentary horizons are intercalated with volcanic rocks in the Kidd- Munro assemblage in the vicinity of the Kidd Creek volcanogenic massive sulphide (VMS) mine. We used a combination of geochemical methods (bulk geochemistry, portable XRF analyzers (PXRF), and laser-ablation ICP-MS analysis of sulfides) of these shales to discriminate between VMS-prospective and VMS-barren horizons. Element signatures associated with hydrothermal plume fallout were also identified and used to determine relative direction to the paleo-venting centre. There are 6 sulfide textural types encompassing laminae and framboids, recrystallized euhedra in laminae, crusts, nodules and concretions, and late overgrowths and porphyroblasts. Bulk geochemical data indicate the presence of a hydrothermal endmember comprised of Ag, Bi, In, Cd, Cu, Pb, Sb, Sn, Tl, Zn. In-situ laser-ablation (LA) ICPMS analyses of pyrite indicate that “dirty”, generally finer grained pyrite contains the highest trace element contents, whereas ”clean”, brighter, coarser grained pyrite contains the lowest trace element contents. Inter- element correlations indicate that Ag, Au, As, Bi, Cu, Pb, Sb, Sn, Tl and Zn are of hydrothermal origin, whereas Co, Ni, Mo, Se, Pt and Te are likely of hydrogenous origin. PXRF can be used to identify and correlate prospective mineralized horizons within exploration drill cores. Keywords: black shale, volcanogenic massive sulfide, exploration vectoring, LA-ICP-MS, portable XRF 1 Introduction Metalliferous sediments are a common component of modern ocean-floor sedimentary sequences, preserving halos of metal dispersion from seafloor hydrothermal vents (Gurvich, 2006). In ancient subaqueous volcanic sequences, sulfidic black shales are also commonly present as intercalations within volcanic sequences, representing hiatuses in volcanic activity and deposition. Some horizons are enriched in ore and associated metals (e.g. Zn, Cu, Ag, Cd, Sn), whereas others are barren, but the dilution of hydrothermal signatures by terrigenous and hydrogenous shale matrix minerals hinders interpretation of metal sources, especially where drilling coverage is limited or element-enrichment is subtle. In addition, later hydrothermal and metamorphic redistribution may have modified any primary exhalative enrichment patterns. We aimed to establish an accurate, precise, robust and cost effective protocol for the evaluation of sedimentary horizons to provide evidence of: a) the presence or absence of hydrothermal metal input; b) the type of hydrothermal activity recorded within, and prospectivity of, any one horizon; and c) the direction, along strike and down dip extent, and relative distance to the coeval venting centre (where a single horizon has been intersected more than once). This was achieved by the combination of geochemical analytical methods including: conventional whole-rock analysis, laser-ablation inductively coupled plasma mass spectrometry (LA- ICP-MS) and portable x-ray fluorescence (PXRF) analysers; each optimised for different spatial Proceedings of the Tenth Biennial SGA Meeting, Townsville, 2009 415