Fluid flow paths in the Middle America Trench and Costa Rica margin

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doi: 10.1130/0091-7613(2000)28<679:FFPITM>2.0.CO;2
Author(s): Silver, Eli; Kastner, Miriam; Fisher, Andrew; Morris, Julie; McIntosh, Kirk; Saffer, Demian
Author Affiliation(s): Primary:
University of California at Santa Cruz, Earth Sciences Department, Santa Cruz, CA, United States
Scripps Institution of Oceanography, United States
Washington University, St. Louis, MO, United States
University of Texas at Austin, United States
Volume Title: Geology (Boulder)
Source: Geology (Boulder), 28(8), p.679-682. Publisher: Geological Society of America (GSA), Boulder, CO, United States. ISSN: 0091-7613 CODEN: GLGYBA
Note: In English. 28 refs.; illus., incl. sect., sketch map
Summary: The hydrology of the subducting plate and its dewatering behavior through the shallow subduction zone is linked to the structure and deformation of the forearc prism, the nature of the seismogenic zone, the composition of seawater for selected elements, and the composition of the residual slab subducted to depths of magma generation at the volcanic arc. Two locally independent systems of fluid flow govern the transport of heat and chemistry through the Costa Rica subduction complex, a dominantly nonaccretionary subduction zone. One fluid system is the margin wedge, decollement, and underthrust sediment section. Fluid sources include local sediment compaction and mineral dehydration at depth. A second flow system occurs in basement, beneath the sedimentary sequence on the incoming plate. This region is characterized by extremely low conductive heat flow, and the sediment overlying basement has pore-water geochemistry similar to that of seawater. Flow nearly parallel to the trench could be directed by permeability associated with faults and driven by a combination of differential heating and earthquake strain cycling.
Year of Publication: 2000
Research Program: ODP Ocean Drilling Program
Key Words: 18 Geophysics, Solid-Earth; Accretionary wedges; Central America; Compaction; Connate waters; Continental margin; Costa Rica; Decollement; Dehydration; East Pacific; Faults; Fluid dynamics; Geochemistry; Geophysical profiles; Geophysical surveys; Heat flow; Hydrochemistry; Leg 170; Marine sediments; Middle America Trench; North Pacific; Northeast Pacific; ODP Site 1039; ODP Site 1040; ODP Site 1043; Ocean Drilling Program; Ocean floors; Pacific Ocean; Permeability; Plate convergence; Pore water; Sediments; Seismic profiles; Subduction zones; Surveys; Trenches; Underthrust faults
Coordinates: N083000 N100000 W0850000 W0863000
Record ID: 2000056041
Copyright Information: GeoRef, Copyright 2019 American Geosciences Institute. Reference includes data supplied by the Geological Society of America, Boulder, CO, United States