Expulsion of fluids from depth along a subduction-zone decollement horizon

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doi: 10.1038/326785a0
Volume Title: Nature (London)
Source: Nature (London), 326(6115), p.785-788. Publisher: Macmillan Journals, London, United Kingdom. ISSN: 0028-0836 CODEN: NATUAS
Note: In English. 21 refs.; illus. incl. sects., sketch map
Summary: Previous results from DSDP Leg 78A (Barbados Ridge) suggest that high fluid P occur along the decollement zone which separates the underthrusting Atlantic Ocean crust and the overthrusting Caribbean plate. On the present Leg 110 of ODP (Ocean Drilling Project), this fault surface was cored in the first penetration of a decollement separating two plates in a subduction zone. The pore-water chemistry, T anomalies and structural observations indicate that the deforming sediments dewater through fracture permeability associated with faults, and the accretionary wedge and underthrust sediments comprise distinct fluid domains separated by a permeability barrier above the decollement zone. Methane-bearing fluids derived from a probable thermogenic source travel >25 km beneath the shallow inclined decollement. (Author's abstract)
Year of Publication: 1987
Research Program: ODP Ocean Drilling Program
Key Words: 07 Marine Geology and Oceanography; 18 Geophysics, Solid-Earth; Accretion; Aliphatic hydrocarbons; Alkanes; Atlantic Ocean; Caribbean Plate; Decollement; Dehydration; Displacements; Faults; Fluid phase; Geopressure; Hydrocarbons; Leg 110; Marine sediments; Methane; North American Atlantic; ODP Leg 110; ODP Site 671; ODP Site 672; ODP Site 673; ODP Site 674; Ocean Drilling Program; Organic compounds; Organic materials; Plate tectonics; Pore water; Sediments; Subduction zones; Tectonophysics; Underthrust faults
Coordinates: N152000 N154500 W0583000 W0590000
Record ID: 1987055759
Copyright Information: GeoRef, Copyright 2019 American Geosciences Institute. Reference includes data from Mineralogical Abstracts, United Kingdom, Twickenham, United Kingdom