Diagenesis and hydrology at the New Hebrides Forearc and intra-arc Aoba Basin

Abstract

In the accretionary wedge extensive fluid flow appears to be confined to highly faulted regions. Although Cl concentrations less than seawater value are common at convergent margins, the New Hebrides margin contains little low-Cl fluid. Br/Cl ratios suggest the low-Cl fluid is from dilution, and δ18O values indicate the water may be derived from mineral dehydration and mixing with meteoric water. The New Hebrides margin exhibits few surface manifestations of venting (e.g. sulfide-oxidizing benthic biological communities, carbonate crusts, mud volcanoes) and thus fluid fluxes may be smaller than at many other margins. -from Author