Accretionary prisms

Fig. 2.36. Tectonic setting of Kyushu, Japan, showing location of (north) Hishikari and Nansatsu (south) deposits in Kirishima arc. Triangle volcanoes younger than Middle Pleistocene stipple accretionary prism of Cretaceous and Tertiary age W-B zone isobath of deep Wadati-Benioff seismic zone MTL Median Tectonic Line BTL Butsuzo Tectonic Line K-P Ridge Kyushu-Palau Ridge (Mitchell and Leach, 1991).

You CF, Chan LH, Spivack AJ, Gieskes JM (1995) Lithium, boron, and their isotopes in ODP Site 808, Nankai Trough sediments and pore waters Implications for fluid expulsion in accretionary prisms. Geology 23 ... 

The Sicily volcanoes are located in a variety of structural settings and on different types of bedrocks. Mount Etna (about 0.6 Ma to present) occurs on the accretionary prism of the Africa-Europe subducting system, at the contact between the Ionian lithosphere, the northern margin of the African plate (Pelagian Block, a promontory of the African foreland) and the corrugated Sicilian-Maghrebian chain (Fig. 8.1 Behncke 2001). 

Treves B (1984) Orogenic belts as accretionary prisms the example of the Northern Apennines. Ofioliti 9 577-618... 

There is a need for further investigations of carbonate reactions and diagenesis and fluid migration in accretionary prisms associated with subduction zones. 

Breeding C. M. and Ague J. J. (2002) Slab-derived fluids and quartz-vein formation in an accretionary prism, Otago Schist, New Zealand. Geology 30, 499-502. 

Fig. 7. Tectonic interpretation showing accretion of mafic and ultramafic oceanic sequences, juvenile volcanic arcs, and accretionary prisms against an older crustal nucleus. Inset shows strength envelopes for the lithosphere showing differential stress (oj-as, MPa) against depth (km) for granite, granulite and dunite (see Jelsma et al. 2001) and Byerlee s (1978) friction relation.

Since the late 1980s focused work on the magnitude of subduction erosion, which is the removal of material from the base of an old accretionary prism or from the fore-arc basement, and its subduction, has been done. Estimates of eroded material can be very large, as much as 35 km per km of arc length per million years (km km Myr ) in Japan and Nicaragua-Costa Rica (von Huene and Culotta, 1989 von Huene and Lallemand, 1990 Ranero et al., 2000 Ranero and von Huene, 2000 Walther et al., 2000 Meschede et al., 1999 Vannucchi et al.,... 

Dissolution of these metastable gas hydrates is a natural consequence of tectonic uplift of accretionary prisms at plate margins and is likely to be partly responsible for the extensive methane plumes above these sites (Herzig Hannington, 2000). The amount of methane that is slowly released from these hydrates can be enough to support a dependent biological community (Suess etal., 1999). 

Olu, K., Lance, S., Sibuet, M., Henry, P., Fiala-Medioni, A. and Dinet, A. (1997) Cold seep communities as indicators of fluid expulsion patterns through mud volcanoes seaward of the Barbados accretionary prism. Deep-Sea Research, 44, 811-841. 

Davis, E.E., Hyndman, R.D., and Villinger, H., 1990. Rates of fluid expulsion across the Northern Cascadia accretionary prism Constraints from new heat flow and multichannel seismic reflection data. Journal of Geophysical Research, 95 8869-8889. 

Teichert, B.M.A., Bohrmann, G, Torres, M., and Eisenhauer, A., 2005b. Eluid sources, fluid pathways and diagenetic reactions across an accretionary prism revealed by Sr and B geochemistry. Earth and Planetary Science Letters, 239 106-121. 

Estimated (solid) fraction subducted (x 1000 km /Myr) from Von Huene and Scholl (1991) a = Type 1 (accretionary prism forms) b = Type 2 (no net accretion) - from Von Huene and Scholl (1991). 

Figure 1. Locations of arc and back-arc systems for which helium isotope data are available (Note Italy is omitted). Trenches are marked by barbed lines (filled barbs = accretionary trenches open barbs = no accretionary prism). Modified from Von Huene and Scholl (1991).

Although volatile flux estimates from back-arc regions vary greatly, the situation is even more poorly constrained for fore-arc regions. We are unaware of any flux estimates for either major volatiles or noble gases. This is in spite of abundant circumstantial evidence for fluid venting in fore-arc regions e.g., serpentinite diapirism in the Marianas (Fryer et al. 1985) and mud volcanism at various accretionary prisms worldwide (Brown... 

MITI well layers (200-270 mbsf) 80% in pore) (hydrate in sand) reduction the highly saturated hydrate layers) (accretionary prism) permeable sand layer... 

Both brachiopods and crinoids occur in the Tertiary deposits exposed in the Scotland District, northeast Barbados. Brachiopods and crinoids occur in the Lower Miocene Bissex Hill nappe, part of the prism cover that rests on the Paleogene basal complex of the Lesser Antillean accretionary prism (Speed, 1994). The brachiopods are micromorphic shells of Argyrotheca and Terebratulina (Fig. 28.2F-I), which occur in Globigerina-rich marlstones and sandstones. These minute shells are homeomorphs and can be confused easily. There is a wealth of crinoid material from Bissex Hill, although limited to only one taxon, the isocrinid Neocrinus decorus (Donovan and Veltkamp, 2001). 

J Geophys Res 85 3867-3877 Baba T, Hori T, Hirano S, Cummins PR, Park J-O, Kameyama M, Kaneda Y (2001) Deformation of a seamount subducting beneath an accretionary prism constraints from numerical simulatioiL Geophys Res Lett 28 1827-1830... 

The Hellenic subduction zone (Jolivet et al. 2013 Ring et al. 2010) extends (Fig. 3) from approximately south of Zakynthos in the west up to Rhodes Island in the east. South of Crete, there is the Mediterranean Ridge which is the accretionary prism formed by the pile of sediments, up to 10 km thick that overlies the oceanic crust. The Hellenic Trench is a scarp in the bathymetry 2-3 km high, which is more clearly developed... 

Fowler, S.R., White, R.S., Louden, K.E., 1985. Sediment dewatering in the Makran accretionary prism. Earth Planet. Sci. Lett. 75, 427-438. 

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