Neodymium isotopic variations of the late Cenozoic sediments in the Jianghan Basin: Implications for sediment source and evolution of the Yangtze River

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• 作者：Lei Shao^a ; ^b ; Chang&rsquo ; an Li^a ; ^c ; ^{chanli_cug@sohu.com} ; ^{chanli@cug.edu.cn} ; Shengyuan Yuan^a ; ^b ; Chunguo Kang^b ; ^d ; Jietao Wang^a ; Ting Li^e
• 关键词：Yangtze River ; Jianghan Basin ; Nd isotope ; Provenance
• 刊名：Journal of Asian Earth Sciences
• 出版年：2012
• 出版时间：2 February 2012
• 年：2012
• 卷：45
• 期：Complete
• 页码：57-64
• 全文大小：912 K

文摘

The Yangtze River originates from eastern Asia and is one of the most important components of the East Asia river system. In this study we applied bulk Nd isotopic analysis to identify the sediment provenance in the Jianghan Basin, middle Yangtze River and tried to provide useful information on the evolvement of the Yangtze River. The fine-grained (<0.058 mm) sediment samples were selected from a continuous borehole in the Jianghan Basin and analyzed for Nd isotopic compositions. The ¹⁴³Nd/¹⁴⁴Nd ratios vary between 0.512042 and 0.512239, with an average of 0.512144. The ¦Å_Nd(0) values vary between ?1.6 and ?.8, with an average of ?.6. Nd isotopic compositions cannot provide compelling evidence to prove whether the Pliocene sediments in the Jianghan Basin were influenced by the source rocks in the Jinshajiang area characterized by extremely high (positive) ¦Å_Nd(0) values. While these source rocks made a great contribution to the Jianghan Basin during the Quaternary. Less negative ¦Å_Nd(0) values reflect preferential erosion of source rocks in the Jinshajiang drainage. The Nd variations reflected changes in erosion patterns during the Quaternary. Based on the provenance analysis of the Jianghan Basin sediments, we propose that the Yangtze River appears to develop into a large river similar as the modern Yangtze no later than the beginning of the Quaternary.