Sr, Nd, and Pb isotope compositions of hemipelagic sediment in the Shikoku Basin: Implications for sediment transport by the Kuroshio and Philippine Sea plate motion in the late Cenozoic
Sr, Nd, and Pb isotope compositions of hemipelagic sediment in the Shikoku Basin: Implications for sediment transport by the Kuroshio and Philippine Sea plate motion in the late Cenozoic
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DOI：
10.1016/j.epsl.2015.04.001
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发表时间：
2015-07
影响因子：
5.3
通讯作者：
Y. Saitoh;T. Ishikawa;M. Tanimizu;M. Murayama;Y. Ujiié;Yuzuru Yamamoto;K. Ujiie;T. Kanamatsu
中科院分区：
文献类型：
--
作者：
Y. Saitoh;T. Ishikawa;M. Tanimizu;M. Murayama;Y. Ujiié;Yuzuru Yamamoto;K. Ujiie;T. Kanamatsu
通过大洋综合钻探C0011站位C0011晚中新世(7 Ma)至今碎屑沉积物的锶-钕-铅同位素组成的时间变化，研究了四国盆地晚新生代半远洋沉积物的物源。C0011站位的碎屑沉积物被解释为起源于日本西南部弧区和东中国海周围陆地的混合沉积物。东中国海的沉积物是由黑潮输送的，而日本的沉积物是由浑浊流、底流和洋流输送的。同位素证据表明，在4.4~2.9 Ma期间，半深海沉积物的主要物源从东中国海逐渐向日本转移，与C0011站位随菲律宾海板块的北移相一致。同时，颗粒尺寸的增加也支持这一解释。这些变化的开始时期为4.4 Ma，与四国盆地岩石圈海沟-正常俯冲的到来或加速密切相关。
The provenance of hemipelagic sediments in the Shikoku Basin during late Cenozoic time was studied through the temporal variations in the Sr–Nd–Pb isotopic compositions of detrital sediments from Integrated Ocean Drilling Program Site C0011 from the late Miocene (7 Ma) to the present. Detrital sediments at Site C0011 are interpreted as a mixture of sediments originating from the southwest Japan arc and lands around the East China Sea. Sediments from the East China Sea were transported by the Kuroshio, while Japanese sediments were transported by turbidity currents, bottom currents, and ocean surface currents. The isotopic evidence suggests that the main source of hemipelagic sediments gradually changed from the East China Sea to Japan from 4.4 to 2.9 Ma, in accordance with the northward movement of Site C0011 with the Philippine Sea plate in this period. A contemporaneous increase in grain size also supports this interpretation. The beginning period of these changes, 4.4 Ma, conforms closely to the postulated advent or acceleration of trench-normal subduction of the Shikoku Basin lithosphere.