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Questions about Subduction approachable with geophysics, field study, laboratory study

Questions about Subduction approachable with geophysics, field study, laboratory study. How Much H 2 O in Incoming Mantle?. → rxn rates & locations (devolatilization), buoyancy, earthquakes(?). Nicaragua: 10 km of 15% serpentine. Lombok: 5 km of 20% serpentine.

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Questions about Subduction approachable with geophysics, field study, laboratory study

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  1. Questions about Subductionapproachable with geophysics,field study, laboratory study

  2. How Much H2O in Incoming Mantle? → rxn rates & locations (devolatilization), buoyancy, earthquakes(?) Nicaragua: 10 km of 15% serpentine Lombok: 5 km of 20% serpentine Tonga: 24 km of 30% serpentine Planert et al. [2010] Ivandicet al. [2010]; Lefeldt et al. [2012] Contreras-Reyeset al. [2011] Costa Rica: 5 km of ≤30% serpentine Chile: 7 km alteration Tonga: ≤8 kmof 60% serpentine Contreras-Reyeset al. [2008] Savage [2012] van Avendonk et al. [2011]

  3. Melt Beneath the Outer Rise? → LAB, forearc volcanism, slab volatiles Hawley et al. (2016) Worzewski et al. (2011) Costa Rica

  4. How Do Fluid & Melt Flow in Wedge? → refertilization, arc magmatism, buoyancy, flow, anisotropy, etc. Nakahigashi et al. (2015) Wilson et al. (2014)

  5. Are Noses Wet? Ryukyu → buoyancy, flow, anisotropy, storage… Abers et al. (in review) isotropic Vp Nagaya et al. (2016) S-wave splitting (anisotropic) few brucite studies; one terrane has 20% (Kawahara et al., 2016)

  6. What Makes a Slow Supra-Slab Layer? → buoyancy, flow, anisotropy, H2O storage, K-magmatism, etc. VS RF reflectivity (Kawakatsu & Watada, 2007) slow crust to 80–90 km 39.5°N Tohoku Moho ΔVs ~+6%

  7. Why is Wedge Conductive? → buoyancy, anisotropy, H2O storage, magmatism Cascadia chlorite → magnetite; but, used Mg#25 chlorite Manthilake et al. (2016) fluid cannot explain anomalous conductivity fluid/melt (McGary et al., 2014)

  8. How Do Noses Deform? by flow? cracking? what is effect of fluids? what is effect on fluids? Escartin et al. (2001); Proctor & Hirth (2016) Nagaya et al. (2016) brittle ductile brittle ductile talc? chlorite? brucite?

  9. What Causes Slow-Slip Events? long-term SSE in W Shikoku because colder slab & thinner crust stabilize brucite (Mizukami et al., 2016)

  10. Is Subducted Carbon Recycled? 20−80% (Dasgupta & Hirschmann, 2010) ≤100% subducted C relaminates upper plate diapirically (Kelemen & Manning, 2015) Kelemen & Manning (2015) Behn et al. (2011)

  11. Is Continental Crust Recycled? <40% of new CC is being recycled(Hacker et al., 2011) ≥100% of new CC is being recycled(Stern & Scholl, 2011) 0% CC has been recycled(Hofmann et al., 2016)

  12. Does Slab Material Transit Wedge? inherited zircons in Cretaceous Cuba arc from subducted sediment (Rojas-Agramonte et al., 2016)

  13. Where are the Wedge Diapirs? Currie et al. (2014) Vogt et al. (2012) Gerya & Meilick (2011) slow density increase or low-viscosity root rapid density increase or high-viscosity root

  14. An Interdisciplinary Approach • geophysical study of active arcs • proxies for slab & wedge fluid, melt, flow • geochemical study of active & fossil arcs • proxies for material cycling • field study of exhumed rocks worldwide • rock record of processes that occurred • laboratory study of rocks & minerals • measure physical properties, incl. deformation

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