CAJ | 학술논문

氧化还原敏感元素是确定古海洋水体氧化还原环境的重要指标，常用的环境判别指标有U/Th, V/Sr, V/Cr, Ni/Co， V/(V+Ni),δU, Ce/Ce*, Eu/Eu*等元素比值。对四川盆地南部宁203井志留系龙马溪组页岩沉积环境的元素地球化学研究结果表明，龙马溪组底部富有机质页岩沉积于缺氧环境，上部为氧化环境。有机碳含量与V/Cr和Ni/Co呈正相关关系，且生物生产力相关元素富集，说明有机质保存与缺氧环境有关。认为在对页岩沉积水体氧化还原条件进行研究时，应将地球化学指标与沉积和古生物特征综合起来得出科学解释。
양화환원민감원소시학정고해양수체양화환원배경적중요지표，상용적배경판별지표유U/Th, V/Sr, V/Cr, Ni/Co， V/(V+Ni),δU, Ce/Ce*, Eu/Eu*등원소비치。대사천분지남부저203정지류계룡마계조혈암침적배경적원소지구화학연구결과표명，룡마계조저부부유궤질혈암침적우결양배경，상부위양화배경。유궤탄함량여V/Cr화Ni/Co정정상관관계，차생물생산력상관원소부집，설명유궤질보존여결양배경유관。인위재대혈암침적수체양화환원조건진행연구시，응장지구화학지표여침적화고생물특정종합기래득출과학해석。
Redox-sensitive elements are the important indicators to determine the redox conditions of ancient ocean environments, and the trace and rare earth element ratios, such as V/Sr, V/Cr, Ni/Co, V/(V+Ni), U/Th, δU, Ce/Ce*and Eu/Eu*ratios, are commonly used as the indices of oxic and/or anoxic depositional environments. The analytic samples are selected from Silurian Longmaxi shale of Well Ning-203 in the south of Sichuan Basin, which is representative of regionally-distributed Longmaxi shale. The analysis of element geochemistry shows that the shale in the downmost part of Longmaxi Formation is organic-rich, which indicates the anoxic depositional environment and the shale in the upper part indicates the oxic environment. The relationships of values with V/Cr or Ni/Co ratios are all positively correlated, and enrichment of biological productivity-related elements reveals that preservation of organic-rich shale is related to anoxic environment. It is suggested that geochemical indices should be combined with sedimentary and paleontological features in studying the redox conditions of ancient sedimentary environments of shale.