Subduction ocean crust

Bebout GE et al. (eds) AGU Geophys Monogr Ser 96 119-133 Peacock SM, Rushmer T, Thompson AB (1994) Partial melting of subducting oceanic crust. Earth Planet Sci Lett 121 227-244... 

Zack T, Tomascak PB, Rudnick RL, Dalpe C, McDonough WF (2003) Extremely light Li in orogenic eclogites The role of isotope fractionation during dehydration in subducted oceanic crust. Earth Planet Sci Lett 208 279-290... 

O, H, C, S, and N isotope compositions of mantle-derived rocks are substantially more variable than expected from the small fractionations at high temperatures. The most plausible process that may result in variable isotope ratios in the mantle is the input of subducted oceanic crust, and less frequent of continental crust, into some portions of the mantle. Because different parts of subducted slabs have different isotopic compositions, the released fluids may also differ in the O, H, C, and S isotope composition. In this context, the process of mantle metasomatism is of special significance. Metasomatic fluids rich in Fe +, Ti, K, TREE, P, and other large ion lithophile (LIE) elements tend to react with peridotite mantle and form secondary micas, amphiboles and other accessory minerals. The origin of metasomatic fluids is likely to be either (1) exsolved fluids from an ascending magma or (2) fluids or melts derived from subducted, hydrothermally altered crust and its overlying sediments. 

Connolly J. A. D. and Kerrick D. M. (2002) Metamorphic controls on seismic velocity of subducted oceanic crust at 100-250 km depth. Earth Planet Set Lett 204, 61-74. 

Peacock S. M. (1993) The importance of blueschist —> eclogite dehydration reactions in subducting oceanic crust. Geol. Soc. Am. Bull. 105, 684-694. 

McDonough W. F. (1991) Partial melting of subducted oceanic crust and isolation of its residual eclogitic lithology. Phil. Trans. Roy. Soc. London A 335, 407—418. 

Based on the work of Philippot et al. (1998), one might expect to observe a certain proportion of chlorine-rich fluid inclusions in mantle-derived xenoliths, but inclusions in these xenoliths are overwhelmingly C02-rich, and chlorine-rich inclusions have not been reported (cf. reviews by Roedder, 1984 Pasteris, 1987 Andersen and Neumann, 2001), with the intriguing exception of the brines reported as inclusions in some diamonds (Johnson et al., 2000 Izraeli et al., 2001). The lack of direct observation of chlorine-rich fluid inclusions in mantle-derived xenoliths may be a result of the lack of examination of appropriate samples that record a previous history as subducted oceanic crust, an absence of these fluids in deeper samples because of participation of these fluids in other petrological processes, such as melt production, or because such fluids do not survive subduction below the slab dehydration limit. Conversely, the presence of chlorine in fluid inclusions in diamonds argues for the existence of chlorine-rich fluids at least in some circumstances in the mantle in the pressure range of diamond stability. 

Ono S., Mibe K., and Yoshino T. (2002) Aqueous fluid connectivity in pyrope aggregates water transport into the deep mantle by a subducted oceanic crust without any hydrous minerals. Earth Planet. Sci. Lett. 203, 895-903. 

Hofmann A. W. and White W. M. (1980) The role of subducted oceanic crust in mantle evolution. Carnegie Yearbook 79, 477-483. 

Integrating Fluid Flux over the Entire Subducted Oceanic Crust An Example... 

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