Subducting volcaniclastic-rich upper crust supplies fluids for shallow megathrust and slow slip.

ABSTRACT: Recurring slow slip along near-trench megathrust faults occurs at many subduction zones, but for unknown reasons, this process is not universal. Fluid overpressures are implicated in encouraging slow slip; however, links between slow slip, fluid content, and hydrogeology remain poorly known in natural systems. Three-dimensional seismic imaging and ocean drilling at the Hikurangi margin reveal a widespread and previously unknown fluid reservoir within the extensively hydrated (up to 47 vol % H₂O) volcanic upper crust of the subducting Hikurangi Plateau large igneous province. This ~1.5 km thick volcaniclastic upper crust readily dewaters with subduction but retains half of its fluid content upon reaching regions with well-characterized slow slip. We suggest that volcaniclastic-ri

SUBMITTER: Gase AC 

PROVIDER: S-EPMC10431706 | biostudies-literature | 2023 Aug

REPOSITORIES: biostudies-literature