Abstract
There exists extensive basic-acidic volcanic rock series in the middle section of the Okinawa Trough. Different types of these volcanic rocks have their own average strontium ratios of 0.704 749, 0.705 062, 0.708 771, 0.704 840 and 0.720 301 with average143Nd/144Nd ratios of 0.512 820, 0.512 673, 0.512 413, 0.512 729 and 0.512 034. These ratios of Sr and Nd isotopes all fall on a theoretic hyperbolic curve of mixing between two end-members of MORB and rhyolitic magma. So we infer that these different kinds of volcanic rocks in the middle Okinawa Trough are the erupted product in different stages of formation and evolution of the trough crust. MORB magma, which had suffered assimilation, mixed with the early-formed crust-derived rhyolitic partial melt mass at different ratios; then, these mixed magma erupted and formed volcanic rock types of the trough. This study indicates that the Okinawa Trough is coming into a stage of submarine spreading from the stage of continental rift.
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References
Ishizuka, H., Kawanobe, Y., Sakai, H., Petrology and geochemistry of volcanic rocks dredged from the Okinawa Trough, an active back-arc basin, Geochemical Journal, 1990, 24: 75.
Chen Lirong, Zhai Shikui, Shen Shunxi, Isotopic characteristics of pumice and its age dating in the Okinawa Trough, Science in China (in Chinese), Ser. B, 1993, 23(3): 324.
Li Weiran, Yang Zuosheng, Zhang Baoming et al., Study of olive tholeiite in the southern Okinawa Trough, Oceanologia et Limnologia Sinica (in Chinese), 1997, 28(6): 665.
Qin Yunshan, Zhai Shikui, Mao Xueying et al., REE characteristics of pumice and its geological significance in the Okinawa Trough, Oceanologia et Limnologia Sinica (in Chinese), 1987, 18(4): 313.
Zhai Shikui, Gan Xiaoqun, Mineralogy and petrology of basalt and their geological significance in a hydrothermal activity area of the Okinawa Trough, Oceanologia et Limnologia Sinica (in Chinese), 1995, 26(2): 115.
Qiu Jiaxiang, Volcanic Petrology, Beijing: Geology Press, 1985, 207–220.
Zhang Zongqing, Ye Xiaojiang, Methods of ICP-MS analysis of rare earth elements and accurate measurement of143Nd/144Nd ratios, Journal of Institute of Geology, Chinese Academy of Sciences, 1987, 17: 105.
Parrs, M., Faugeres, J. C., Grousset, F. et al., Sr-Nd isotopes as tracers of fine-grained detrital sediments: the south Barbados acretionary prism during the last 150 kyr, Marine Geology, 1997, 136: 225.
Claude, J. A., Bruno, H., Ariel, P. et al., Topology in isotopic multispace and origin of mantle chemical heterogeneities, Earth and Planetary Science Letters, 1986/1987, 81: 319.
Volpe, A. M., Maedougall, J. D., Hawkines, J. W., Mariana Trough basalt (MTB): trace element and Sr-Nd isotopic evidence for mixing between MORB-like and Arc-like melts, Earth and Planetary Science Letters, 1987, 82: 241.
Faure, G., Principle of Isotope Geology, New York: Wiley, 1986, 117–247.
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Meng, X., Chen, Z., Du, D. et al. Sr, Nd isotope geochemistry of volcanic rock series and its geological significance in the middle Okinawa Trough. Sci. China Ser. D-Earth Sci. 43, 458–463 (2000). https://doi.org/10.1007/BF02875307
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DOI: https://doi.org/10.1007/BF02875307