Molybdenum systematics of subducted crust record reactive fluid flow from underlying slab serpentine dehydration.

ABSTRACT: Fluids liberated from subducting slabs are critical in global geochemical cycles. We investigate the behaviour of Mo during slab dehydration using two suites of exhumed fragments of subducted, oceanic lithosphere. Our samples display a positive correlation of δ^98/95Mo_{NIST 3134} with Mo/Ce, from compositions close to typical mantle (-0.2‰ and 0.03, respectively) to very low values of both δ^98/95Mo_{NIST 3134} (-1‰) and Mo/Ce (0.002). Together with new, experimental data, we show that molybdenum isotopic fractionation is driven by preference of heavier Mo isotopes for a fluid phase over rutile, the dominant mineral host of Mo in eclogites. Moreover, the strongly perturbed δ^98/95Mo_{NIST 3134} and Mo/Ce of our samples requires that th

SUBMITTER: Chen S 

PROVIDER: S-EPMC6803652 | biostudies-literature | 2019 Oct

REPOSITORIES: biostudies-literature