Identification:
Title:
An empirical relationship between velocity and porosity for underthrust sediments in the Nankai Trough accretionary prism
Year:
2005
Source:
In: 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., Sanchez-Gomez, 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, Brueckmann, 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, 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
Publisher:
Texas A&M University, Ocean Drilling Program, College Station, TX, United States
Volume:
190/196
Issue:
Pages:
Abstract:
An empirical relationship between compressional wave velocity and porosity was developed for underthrust sediments in the Shikoku Basin of the Nankai accretionary prism. Shipboard core and logging measurements of velocity and porosity from Ocean Drilling Program Legs 131, 190, and 196 were used to define a new velocity-porosity transform based on an existing formulation. The new transform includes a critical porosity transition. Corrections were calculated and applied to shipboard core measurements to account for unloading from in situ conditions. The results from the velocity-porosity transform indicate the Shikoku Basin sediments follow a normal consolidation curve. A critical porosity transition is crossed at a fractional porosity of approximately 0.30 between the protothrust and frontal thrust zones of the accretionary prism. Although an accurate critical porosity transition was fit to these data, the critical porosity transition occurs over a range of porosity. The Shikoku Basin formulation represents a significant improvement over previous velocity-porosity formulations.
Language:
English
Genre:
Serial
Rights:
URL: