Paleoceanographic Environment of Japan Sea Deduced from Chemical and Isotopic Features of Miocene-Pliocene Sedimentary Rocks
Paleoceanographic Environment of Japan Sea Deduced from Chemical and Isotopic Features of Miocene-Pliocene Sedimentary Rocks
复制标题
从中新统-上新统沉积岩化学和同位素特征推断日本海古海洋环境
DOI：
10.5026/jgeography.112.4_586
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发表时间：
2003
期刊：
影响因子：
--
通讯作者：
M. Nohara
中科院分区：
文献类型：
--
作者：
S. Kimura;N. Shikazono;M. Nohara
对日本北部男鹿半岛中中新世至上新世早期沉积岩采集的岩石样品进行化学和同位素分析（锶同位素比、主量元素、微量元素、稀土元素、总碳、氮和硫含量），以阐明日本海的古海洋环境。研究的岩石包括按地层升序排列的西黑泽、恩纳川和船川地层的页岩。下层（约12.6-11.4 Ma）、中层（约10.5-9.0 Ma）和上层（约8.3-7.0 Ma）的恩纳川沉积岩具有高Mo/Al、P/Al、Ba/Al比和总有机碳含量的特征。正Eu异常、K/Ti比值和87Sr/86Sr比值在同一层位也较高。这些地球化学变化意味着高初级生产力、古海洋深处的还原条件以及石油源岩的形成是由深层海水的上升引起的。深层海水的上涌被认为是受到亚洲大陆强风的影响，这与喜马拉雅山和西藏地区的隆起有关。
Chemical and isotopic analyses (Sr isotopic ratio, major element, trace element, rare earth element, total carbon, nitrogen, and sulfur contents) of rock samples collected from middle Miocene to early Pliocene sedimentary rocks, Oga Peninsula, northern Japan were performed to elucidate the paleoceanographic environment of Japan Sea. The rocks studied include shale from Nishikurosawa, Onnagawa, and Funakawa formations in stratigraphically ascending order. The Onnagawa sedimentary rocks in the lower (ca. 12.6-11.4 Ma), middle (ca. 10.5-9.0 Ma), and upper (ca. 8.3-7.0 Ma) horizons are characterized by high Mo/Al, P/Al, and Ba/Al ratios and total organic carbon content. Positive Eu anomaly, K/Ti ratio and 87Sr/86Sr ratio are also high in the same horizons. These geochemical variations imply that high primary productivity, and reducing condition of deep paleoocean, and formation of petroleum source rocks were caused by an upwelling of deep seawater. The upwelling of deep seawater is considered to have been influenced by strong winds from the Asian continent, which was related to the uplift of Himalayan and Tibetan regions.