Iron and sulfur geochemistry of deep biosphere sediments from ODP Leg 207 site 1259

The iron and sulfur geochemistry was investigated on squeeze cake samples retrieved from deep biosphere sediments during ODP Leg, Demerara Rise, southern North Atlantic. Vertical profiles from 5 sites were analyzed using different chemical extraction methods followed by spectrophotometric geochemical analyses and organic sulfur using elemental analysis, to understand the carbon-iron-sulfur interactions during and black shale formation and upon diagenesis in the times after.