Learn More
Mid-ocean ridge basalts (MORB) are a consequence of pressure-release melting beneath ocean ridges, and contain much information concerning melt formation, melt migration and heterogeneity within the upper mantle. MORB major element chemical systematics can be divided into global and local aspects, once they have been corrected for low pressure fractionation(More)
the slab hydration source that permits refractory mantle to flow) that may have promoted the propagation of the CLSC to replace this system. Spreading in the Lau back-arc basin is at present well-organized, as at mid-ocean ridges 5,12 , but, as we have shown, the supply of magma is modulated by mantle wedge compositional controls and arc melt additions.(More)
[1] Subduction zone magmas are characterized by high concentrations of H 2 O, presumably derived from the subducted plate and ultimately responsible for melting at this tectonic setting. Previous studies of the role of water during mantle melting beneath back-arc basins found positive correlations between the H 2 O concentration of the mantle (H 2 O o) and(More)
Investigations of a variety of continental rifts and margins worldwide have revealed that a considerable volume of melt can intrude into the crust during continental breakup, modifying its composition and thermal structure. However, it is unclear whether the cause of voluminous melt production at volcanic rifts is primarily increased mantle temperature or(More)
Convergent margin volcanism is ultimately fed by magmas generated in the mantle, but the connection between the mantle and the eruption at the surface is typically obscured by cooling, crystallization and magma mixing within the crust. Geophysical techniques are also not very effective in the lower and middle crust, where seismic events are rare and(More)
Processes of melt generation and transport beneath back-arc spreading centres are controlled by two endmember mechanisms: decompression melting similar to that at mid-ocean ridges and flux melting resembling that beneath arcs. The Lau Basin, with an abundance of spreading ridges at different distances from the subduction zone, provides an opportunity to(More)
a r t i c l e i n f o a b s t r a c t Keywords: Tohoku earthquake Pacific plate stratigraphy shallow subduction structure ODP Site 1149 DSDP Site 436 IODP Expedition 343 We determine the trace element stratigraphy of Site C0019, drilled during the Japan Fast Trench Drilling Project (JFAST) International Ocean Discovery Program (IODP) Expedition 343, to(More)
Material in this publication may be copied without restraint for library, abstract service, educational, or personal research purposes; however, republication of any portion requires the written consent of the Director, Any opinions, findings, and conclusions or recommendations expressed in this publication are those of the author(s) and do not necessarily(More)
During Leg 185 two deep-water sites will be drilled, one seaward of the Mariana Trench (Ocean Drilling Program Hole 801C) and one seaward of the Izu-Bonin Trench (Site BON-8A). The primary objectives are to investigate sediment subduction along this arc-trench system and to characterize the chemical fluxes during alteration of the oceanic crust. Despite the(More)
  • 1