Regional-scale melt-rock interaction in lherzolitic mantle in the Romanche Fracture Zone (Atlantic Ocean)

摘要: Abstract Mantle-derived peridotites recovered from the Romanche Fracture Zone fall in two compositional groups. Group 1 nearly undepleted lherzolites, indicating a very low degree of melting, are prevalent western part transform. 2 peridotites, with higher Mg/Fe ratio but enriched Ti and incompatible trace elements generally containing plagioclase, common eastern transform, where samples also present. lherzolites consistent relatively upper mantle temperature below region. can be explained by reaction between melt lherzolite, at close to peridotite solidus, still upwelling mantle.