Microbial δ34S fractionation in a shallow submarine hydrothermal vent system, Vulcano, Italy Stam, M. C. ; Mason, P. R. D. ; Amend, J. P. ; Viňas, M. ; Gerritse, J. Abstract Publication: Geochimica et Cosmochimica Acta Supplement Pub Date: July 2008 Bibcode: 2008GeCAS..72..891S