鄂尔多斯西南缘水泉岭组碳酸盐岩地球化学特征

发布时间：2018-08-18 18:01

【摘要】：对采自鄂尔多斯盆地西南缘中奥陶统水泉岭组的碳酸盐岩进行详细的元素地球化学分析,探讨各特征元素对古环境、古气候的指示意义。研究认为,研究区所测样品中典型陆源特征元素(如Al,Th,Zr等)的含量均较低,Y/Ho比值平均为41.27,均反映出研究区碳酸盐岩较少受陆源成分影响的特征;δEu和δCe对ΣREE未呈现出良好的相关性,也不具备明显的Eu正异常,这说明其受成岩作用和热液作用的影响也较为有限,所采样品能够较好地反映原始沉积环境。此外,结合MgO/CaO,V/(V+Ni),Th/U,Sr/Ba,V/Ni和m值等特征元素分析,研究区中奥陶统水泉岭组碳酸盐岩早期发育在高温潮湿且盐度较大的还原环境之中,而晚期则表现出盐度相对降低的弱氧化还原环境。
[Abstract]:The element geochemistry of carbonate rocks collected from the Middle Ordovician Shuiquanling formation in the southwestern margin of Ordos Basin is analyzed in detail and the significance of each characteristic element to paleoclimate and paleoclimate is discussed. The study found that, The contents of typical land-based characteristic elements (such as Albor, Th, Zr, etc.) in the samples measured in the study area are all relatively low, the average value of Y / Ho ratio is 41.27, which reflects that carbonate rocks in the study area are less affected by continental composition, and 未 EU and 未 ce have no good correlation with 危 REE, and 未 EU and 未 ce do not show a good correlation with 危 REE, and 未 EU and 未 ce do not show a good correlation with 危 REE. There is no obvious positive EU anomaly, which indicates that the EU positive anomaly is limited by diagenesis and hydrothermal process, and the samples can reflect the original sedimentary environment well. In addition, based on the analysis of the characteristic elements of MgO / CaOV / (V Ni) / Thr / U / Sr / Ba / V / Ni and m values, the carbonate rocks of the Middle Ordovician Shuiquanling formation developed in a high temperature, humid and high salinity reduction environment in the early stage, while in the late stage they showed a weak redox environment with relatively low salinity.
【作者单位】：西北大学大陆动力学国家重点实验室/地质学系;
【基金】：国家自然科学重点基金资助项目(41330315) 中国地质调查局专项基金资助项目(12120113039900;12120114009201)
【分类号】：P588.245

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