Abstract
The major aim of this study is to put forwad a valid model to explain the gravity anomalies observed over the Okinawa Trough which the crustal structure and a reasonable model of the downgoing slab themselves cannot explain. The result of inversion indicates that the lithosphere above the center of the trough thins out to 45% of the normal thickness (63 km) of the lithosphere of the East China Sea.
Fur ther, the originations of lithospheric force are discussed. The tensional stress of about 160 bar arising from density contrast in the Okinawa Trough is recognized to be the most important causative factor in the stretching of the trough.
Similar content being viewed by others
References
Abe Katsuyuki, 1980. Upper mantle structure of the Philippine Sea.Oceanic Geological Research (N). pp. 263–267. (Chinese translation)
Anderson, R.N., et al., 1976. Geochemical constrains at converging plate boundaries: I. Dehydration in the downgoing slab.Geophys. J. Roy. Astron. Soc. 44: 333–357.
Chen Shenzhao, 1983. The characteristics of the deep structure of the South China Sea and the environmental seas.Journal of Nanjing University (Nature Sciences) 3: 521–535.
Feng Rui, et al., 1981. Crustal structure in China from surface waves.Acta Seismologia Sinica 3(4) 335–350 (in Chinese with English abstract)
Grow, J.A., et al., 1975. Evidence for high-density crust and mantle beneath the Chile Trench due to the descending lithosphere.J.G.R. 80: 1449–1458.
Herman, B. M., et al., 1979. Extensional structure in the Okinawa Trough.AAPG Mer. 29: 199–208.
Jin Xingchun, et al., 1984. The primary analysis of the crustal charactristics and the anomalous mantle of the Okinawa Trough.Marine Geology and Quaternary Geology 14(3): 17–25. (in Chinese)
Krishna V.G. et al., 1984a. Upper mantle velocity structure in the Ryukyu and Taiwan-Luzon ares.J. Phy. Earth 32: 63–84.
Krishna, V.G., et al., 1984 b. Upper mantle velocity structure in the New Guinea and Solouon Islands Regions.J. Phys. Earth 32: 339–371.
Kusznir, N.J. and Bott, M.H.P., 1977. Stress concentration in the upper lithosphere caused by underlying viscoelastic creep.Tectonophysics 43: 247–256.
Lee, C-S, 1980. Origin of a back-arc basin.Marine Geology 35: 219–241.
Lee Quanxin. 1982. The Origin of Okinawa Trough.Acta Oceanologica Sinica 4(3): 324–334.
Muranchi, S., et al., 1968. Crustal structure of the Philippine Sea.Journal of Geophysical Research 73(10): 3143–3171.
Nafi Toksoz, M., et al., 1978. Numerical studies of back-are convertion and the formation of mariginal basins.Tectonophysics 50: 177–196.
Park, M.J.M., et al., 1983. Visco-elastic modeling of lithospheric stress arising from density contrasts. Geophys.J.K. Astr. Soc. 74: 905–914.
Ringwood, A.E., 1977. Petrogenesis in Island Are Systems in Island Ares, Deep Sea Trenches, and Back-Are Basins. Maurice Ewing Ser. Vol. 1. edited by M. Talwani and W.C. Pitmann pp. 311–324.
Sager, W.W., 1980. Marianas are structure inferred from gravity and seismic data.J.G.R. 25(B10): 5382–5388.
Song Zhonghe, et al., 1986. P-wave velocity structure of the upper mantle on the mainland and the marginal seas of China.Acta Seismologica Sinica 8(3): 25–36.
Wageman, B.M., et al., 1970. Structure framework of East China Sea and Yellow Sea,Bull. Amer. Ass. Petrol. Geol. 54: 1611–1643.
Author information
Authors and Affiliations
Additional information
Contribution No. 1487 from Institute of Oceanology. Academia Sinica
Rights and permissions
About this article
Cite this article
Yang, S. The crust and upper mantle structure and the stretching mechanism of the Okinawa Trough. Chin. J. Ocean. Limnol. 6, 135–143 (1988). https://doi.org/10.1007/BF02847833
Received:
Issue Date:
DOI: https://doi.org/10.1007/BF02847833