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Leeman et al 2004 Moriguti et al 2004 Rosner et al 2003 PowerPoint Presentation
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Leeman et al 2004 Moriguti et al 2004 Rosner et al 2003

Leeman et al 2004 Moriguti et al 2004 Rosner et al 2003

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Leeman et al 2004 Moriguti et al 2004 Rosner et al 2003

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  1. Low T° Slab Fluids S. Sandwich, Tonga Mantle MORB/OIB High T° slab fluids 1.6 Leeman et al 2004 Moriguti et al 2004 Rosner et al 2003 Morris and Ryan (2003): TWO non-mantle high B reservoirs are required to explain d11B in arcs: one with very high and one with very low d11B

  2. Sediments (Plank and Langmuir 1998) Altered Ocean Crust (Kelley et al 2003 High B, variably high Ba fluid component Depleted Mantle (Salters and Stracke 2004) A B-depleted, sediment-derived component?

  3. Mariana Forearc Serpentinite show elemental profiles… Depleted Mantle (Salters and Stracke, 2004 • Strongly enriched in B, As, Sb, Cs (“FME’s”) • Moderately enriched in Rb, Li, K, (maybe Sr, Ba, Pb) • Strongly Elevated d11B (+13-+18‰: Benton et al 2001; Savov et al submitted) • 87Sr/86Sr: ~0.705 (Savov et al 2005; 2007) • NOT enriched in: U, Th, • STRONGLY depleted in: REE, HFSE • 143Nd/144Nd, U-Th-Pb, Os isotopes: variable (reflecting protolith; Hattori and Guillot 2007)

  4. …that complement “fluid mobile” element profiles in slab sediments and arc lavas… …suggesting a “forearc” component derived from shallow slab fluid releases, transported in serpentinites dragged down into arc root zones.

  5. Forearc Porefluids (Mottl et al 2004) Strongly Elevated B, Cs, Rb (also As); slightly elevated K, Ba Depleted in Sr, Li Regular changes related to metamorphic changes with depth.