Heat flow and fluid flow regime in the western Nankai accretionary prism

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doi: 10.1016/0012-821X(92)90105-5
Author(s): Yamano, M.; Foucher, J. P.; Kinoshita, M.; Fisher, A.; Hyndman, R. D.; Taira, A.; Hill, I.; Firth, J. V.; Berner, U.; Brückmann, W.; Byrne, T.; Chabernaud, T.; Gamo, T.; Gieskes, Joris M.; Karig, D.; Kastner, M.; Kato, Y.; Lallemant, S.; Lu, R.; Maltman, Alex J.; Moran, K.; Moore, G.; Olafsson, G.; Owens, B.; Pickering, K.; Siena, F.; Taylor, E.; Underwood, M.; Wilkinson, C.; Zhang, J.
Ocean Drilling Program, Leg 131, Shipboard Scientific Party
Author Affiliation(s): Primary:
Scripps Inst. Oceanogr., Geol. Res. Div., La Jolla, CA, United States
Ec. Norm. Supér., France
Volume Title: Fluids in convergent margins
Volume Author(s): Kastner, M., editor; Le Pichon, Xavier
Source: Earth and Planetary Science Letters, 109(3-4), p.451-462; Fluids in subduction zones, Paris, France, Nov. 5-6, 1991, edited by M. Kastner and Xavier Le Pichon. Publisher: Elsevier, Amsterdam, Netherlands. ISSN: 0012-821X CODEN: EPSLA2
Note: In English. 44 refs.; illus. incl. sects., sketch maps
Summary: Recent closely spaced probe measurements showed that the heat flow on the Nankai Trough floor is particularly high near the deformation front. The heat flow distribution suggests that warm fluid flows seaward, possibly along the decollement, and locally rises toward the sea-floor along some channels, resulting in both the regional and local heat flow anomalies. Contrary to this inference, no active localized fluid flow was detected at Site 808. The T measured at six depths down to 347 m below sea-floor just below the frontal thrust can be well explained by conductive heat flow of 125-130 mW/m2. No geochemical anomaly associated with present-day pore fluid movement was observed in cores recovered from the frontal thrust or the decollement. On the other hand, the high heat flow at Site 808 requires some heat source below 350 m bsf. There is a possibility that the fluid flow in the Nankai accretionary prism is localized and transient, and thus was not detected at this single drill site.
Year of Publication: 1992
Research Program: ODP Ocean Drilling Program
Key Words: 18 Geophysics, Solid-Earth; 20 Geophysics, Applied; Accretionary wedges; Anomalies; Dehydration; Fluid phase; Gas hydrates; Geophysical surveys; Heat flow; Leg 131; Leg 132; Marine sediments; Nankai Trough; North Pacific; Northwest Pacific; ODP Site 808; Ocean Drilling Program; Ocean floors; Pacific Ocean; Pore water; Sediments; Surveys; Thermal regime; Troughs; West Pacific
Coordinates: N321000 N323000 E1350500 E1345000
Record ID: 1992024696
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