Legs 190 and 196 synthesis; deformation and fluid flow processes in the Nankai Trough accretionary prism

Online Access: Get full text
doi: 10.2973/odp.proc.sr.190196.201.2005
Author(s): Moore, Gregory F.; Mikada, Hitoshi; Moore, J. Casey; Becker, Keir; Taira, Asahiko
Ocean Drilling Program, Leg 190, Shipboard Scientific Party, College Station, TX
Author Affiliation(s): Primary:
University of Hawaii at Manoa, Department of Geology and Geophysics, Honolulu, HI, United States
Other:
University of Tokyo, Japan
Japan Marine Science and Technology Center, Japan
Volume Title: Proceedings of the Ocean Drilling Program; scientific results; deformation and fluid flow processes in the Nankai Trough accretionary prism; coring, logging while drilling and advanced CORKs covering Legs 190 to 196 of the cruises of the drilling vessel JOIDES Resolution; Sydney, Australia, to Yokohama, Japan, Sites 1173-1178, 23 May-16 July 2000; and Keelung, Taiwan, to Kochi, Japan, Sites 808-1173, 2 May-1 July 2001
Volume Author(s): Moore, Gregory F.; Taira, Asahiko; Klaus, Adam; Becker, Keir; Becker, Luann; Boeckel, Babette; Cragg, Barry A.; Dean, P. Allison; Fergusson, Christopher L.; Henry, Pierre; Hirano, Satoshi; Hisamitsu, Toshio; Hunze, Sabine; Kastner, Miriam; Maltman, Alex J.; Morgan, Julia K.; Murakami, Yuki; Saffer, Demian M.; Sánchez-Gómez, Mario; Screaton, Elizabeth J.; Smith, David C.; Spivack, Arthur J.; Steurer, Joan F.; Tobin, Harold J.; Ujiie, Kohtaro; Underwood, Michael B.; Wilson, Moyra E. J.; Mikada, Hitoshi; Moore, J. Casey; Austin, Gary L.; Bangs, Nathan L. B.; Bourlange, Sylvain; Broilliard, Julien; Brückmann, Warner; Corn, Ernest Ray; Davis, Earl E.; Flemings, Peter B.; Goldberg, David S.; Gulick, Sean P. S.; Hansen, Martin Bak; Hayward, Nathan; Hills, Denise J.; Ienaga, Masanori; Ishiguro, Hiroyasu; Kinoshita, Masataka; Macdonald, Robert D.; McNeill, Lisa; Obana, Shinichi; Hong, Ong Swee; Peacock, Sheila; Pettigrew, Thomas L.; Saito, Saneatsu; Sawa, Takao; Thaiprasert, Nophawit; Tsurumi, Hikaru
Source: Proceedings of the Ocean Drilling Program; scientific results; deformation and fluid flow processes in the Nankai Trough accretionary prism; coring, logging while drilling and advanced CORKs covering Legs 190 to 196 of the cruises of the drilling vessel JOIDES Resolution; Sydney, Australia, to Yokohama, Japan, Sites 1173-1178, 23 May-16 July 2000; and Keelung, Taiwan, to Kochi, Japan, Sites 808-1173, 2 May-1 July 2001, Gregory F. Moore, Asahiko Taira, Adam Klaus, Keir Becker, Luann Becker, Babette Boeckel, Barry A. Cragg, P. Allison Dean, Christopher L. Fergusson, Pierre Henry, Satoshi Hirano, Toshio Hisamitsu, Sabine Hunze, Miriam Kastner, Alex J. Maltman, Julia K. Morgan, Yuki Murakami, Demian M. Saffer, Mario Sánchez-Gómez, Elizabeth J. Screaton, David C. Smith, Arthur J. Spivack, Joan F. Steurer, Harold J. Tobin, Kohtaro Ujiie, Michael B. Underwood, Moyra E. J. Wilson, Hitoshi Mikada, J. Casey Moore, Gary L. Austin, Nathan L. B. Bangs, Sylvain Bourlange, Julien Broilliard, Warner Brückmann, Ernest Ray Corn, Earl E. Davis, Peter B. Flemings, David S. Goldberg, Sean P. S. Gulick, Martin Bak Hansen, Nathan Hayward, Denise J. Hills, Masanori Ienaga, Hiroyasu Ishiguro, Masataka Kinoshita, Robert D. Macdonald, Lisa McNeill, Shinichi Obana, Ong Swee Hong, Sheila Peacock, Thomas L. Pettigrew, Saneatsu Saito, Takao Sawa, Nophawit Thaiprasert and Hikaru Tsurumi; Ocean Drilling Program, Leg 190, Shipboard Scientific Party, College Station, TX; Ocean Drilling Program, Leg 196, Shipboard Scientific Party, College Station, TX. Proceedings of the Ocean Drilling Program, Scientific Results (CD ROM), Vol.190/196, 26p. Publisher: Texas A&M University, Ocean Drilling Program, College Station, TX, United States. ISSN: 1096-2514
Note: In English. Also available on CD-ROM in PDF format and on the Web in PDF or HTML. 55 refs.CD-ROM format, ISSN 1096-2514; WWW format, ISSN 1096-7451; illus., incl. sects., sketch maps
Summary: Ocean Drilling Program Legs 190 and 196 were a two-part program to study deformation and fluid flow in the central Nankai Trough off Shikoku Island. During Leg 190 two reference sites were drilled outboard of the trench (Sites 1173 and 1178), one site into the protothrust zone (Site 1174), two sites into a trench slope basin above a major out-of-sequence thrust (Sites 1175, 1176), and one site into an older portion of the accretionary prism. During Leg 196, Sites 1173 and 808 (drilled through the frontal thrust during Leg 131) were revisited, employing logging while drilling and installing two Advanced Circulation Obviation Retrofit Kits (ACORKs). Our reference sites defined the stratigraphic framework and physical properties baseline of the accreting/subducting Shikoku Basin sedimentary section. The proto-thrust and frontal thrust sites documented the dewatering and deformation processes at the toe of the accretionary prism. Porosity comparisons between Sites 1173 and 808 suggest that elevated fluid pressures occur beneath the decollement at Site 808. Initial measurements from the ACORK at Site 808 indicate a pressure pulse apparently from the decollement. Negative chloride anomalies at Sites 1174 and 808 could be due to fluid flow from deeper in the prism, but active smectite dehydration could also be responsible for the anomalies. Resistivity imaging of the frontal thrust shows borehole breakouts with principal stress orientations consistent with core-scale structures and plate convergence directions. Combined with a three-dimensional seismic reflection survey, our drilling data suggest that the decollement developed because of overpressuring beneath a diagenetic phase transition. Seismic data further suggest that the velocity-density inversion at the decollement at Sites 1174 and 808 is obliterated after underthrusting to seismogenic depths. The slope basin sites provide key evidence that the large out-of-sequence thrust was very recent and that the outer 40 km of the accretionary prism was built within the past 1 m.y.
Year of Publication: 2005
Research Program: ODP Ocean Drilling Program
Key Words: 07 Marine Geology and Oceanography; Accretionary wedges; Cores; Decollement; Deformation; Flows; Geomicrobiology; Geophysical methods; Leg 190; Leg 196; Lithostratigraphy; Nankai Trough; North Pacific; Northwest Pacific; Ocean Drilling Program; Ocean floors; Pacific Ocean; Porosity; Sea water; Shikoku Basin; Troughs; West Pacific
Coordinates: N310000 N340000 E1360000 E1330000
Record ID: 2005060937
Copyright Information: GeoRef, Copyright 2019 American Geosciences Institute.