R8: Metamorphic rocks and tectonics

[R8-08] Mixing and fluid-related processes in the slab-mantle interface during incipient subduction: records from the Dalrymple Amphibolite, Philippines

[Presentation award entry]

*Gabriel Theophilus Vinalay Valera¹, Tetsuo Kawakami¹, Betchaida Duetes Payot² (1. Kyoto Univ., 2. Univ. of the Philippines)

Keywords:slab-mantle interface, fluid infiltration, Dalrymple Amphibolite

The slab-mantle interface separates the downgoing slab from the mantle wedge in arcs. This shear zone is the locus of complex mechanical and fluid-related processes which control the chemistry of fluids and/or melts passing through. During incipient subduction, the slab-mantle interface is sometimes preserved at the base of the ophiolite as a high grade metamorphic sequence. In this study, we present the petrographic and geochemical signatures of the Dalrymple Amphibolite, a mélange sequence which occur at the base of the Palawan Ophiolite, Philippines.