crust: implications for the sources of metals

10 Volcanogenic Massive Sulphide (VMS) deposits are commonly enriched in Cu, Zn and 11 Pb and can also be variably enriched in Au, As, Sb, Se and Te. The behaviour of these elements 12 during hydrothermal alteration of the oceanic crust is not well known. Ocean Drilling Program 13 (ODP) Hole 1256D penetrates a complete in-situ section of the upper oceanic crust providing a 14 unique sample suite to investigate the behaviour of metals during hydrothermal alteration. A 15 representative suite of samples was analysed for Au, As, Sb, Se and Te using low detection limit 16 methods, and a mass balance of metal mobility has been carried out through comparison with a 17 fresh Mid-Oceanic Ridge Basalt (MORB) glass database. The mass balance shows that Au, As, 18 Se, Sb, S, Cu, Zn and Pb are depleted in the sheeted dyke and plutonic complexes with mobilities 19 of -46±12 %, -27±5 %, -2.5±0.5 %, -27±6 %, -8.4±0.7 %, -9.6±1.6 %, -7.9±0.5 % and -44±6 % 20 respectively. Arsenic and Sb are enriched in the volcanic section due to seawater-derived fluid 21 Manuscript Click here to download Manuscript: MIDE-D-14-00144-1-Patten-revised.docx