complex of the Nankai Trough and reveal the thermal history with drill core analyses. The area was originally a basin (Shikoku Basin) with active hydrothermal activity during its formation. As basin formation stopped and sedimentation took place, the sediments acted like a blanket to trap the heat below. Rapid sedimentation resulted in a greater retention of heat. There was also underground fluid flow with the fluids being much hotter than the present-day temperature of the sediments, which affected mineralization and, potentially, the physical and biological properties of the region. See also Nankai Trough gas hydrate site Subduction Zone Note References Baba, T., Cummins, P. R., 2005, Contiguous rupture area of two Nankai Trough earthquakes revealed by high resolution tsunami waveform inversion, Geophysical Research Letters, v. 32, doi:1029/2004GL022320. Collett, T. S., 2002, Energy resources potential of natural gas hydrates, AAPG Bulletin, v. 86, pp. 1971–92. Colwell, F., Matsumoto, R., Reed, D., 2004, A Review of gas hydrate, geology and biology of the Nankai Trough, Chemical Geology, v. 205, pp. 391–404. Davis, E., Becker, K., Wang, K., Obara, K., Ito, Y., Kinoshita, M., 2006, A discrete episode of seismic and aseismic deformation of the Nankai trough subduction zone accretionary prism and incoming Philippine Sea plate, Earth and Planetary Science Letter 242, pp. 73–84. DeMets, C., Gordon, R., Argus, D., Stein, S., 1990, Current plate motions, Geophysical Journal International, v. 101, pp. 425–478. Demets, C., Gordon, R., ARgus, D., Stein, S., 1994, Effects of recent revisions to the geomagnetic reversal time scale on estimates of current plate motions, Geophysical Research Letters, v. 21, n. 20 pp. 2191–2194. Hori, T., Kato, N., Hirahara, K., Baba, T., Keneda, Y., 2004, A numerical simulation of earthquake cycles along the Nakai Trough in southwest Japan: lateral variation in frictional property due to the slab geometry controls the nucleation position, Earth and Planetary Science Letter, v. 22, pp. 215–226. Kastner, 2001, Gas ydrates in convergent margins: formation, occurrence, geochemistry, and global significance. Natural Gas Hydrates: Occurrence, Distribution and Detection. Geophysical Monograph, vol. 124. American Geophysical Union Washington, DC, pp. 67–86. Krason, 1994, Study of 21 marine basins indicates wide prevalence of hydrates, Offshore, August, pp. 34–35. Ike, T., More, G., Okano, T., Kuramoto, S., Taira, A., Along strike changes in basement topography and sediment thickness in the northern Shikoku Basin: Variable inputs to the Nankai Trough Seismogenic Zone, EOS Transaction, American Geophyiscal Union, vol. 85, Fall Meeting Supplements.