Diagenesis of organic matter, isotopic composition of calcite veins in basement basalt and pore water in sediment - Barbados Ridge complex, Deep Sea Drilling Project Leg 78A.

Abstract

The concentrations of organic carbon and 13C in organic carbon decrease with depth, whereas the concentration of dispersed hydrocarbons increases slightly with depth. These trends may reflect the slow oxidation of organic matter, with selective removal of 13C and slow conversion of the residual organic matter to hydrocarbons observed at about 250m sub-bottom at two of the drilling sites. Basement basalt alteration and precipitation of vein calcite occurred in contact either with warmer Campanian seawater or, later, with pore water, after burial to depths of 200-300m.-from Author