鄂尔多斯盆地张家滩页岩元素地球化学特征及与有机质富集的关系

发布时间：2018-02-21 17:23

本文关键词： 有机质富集主微量元素沉积环境张家滩页岩鄂尔多斯盆地　出处：《煤炭学报》2017年06期 　论文类型：期刊论文

【摘要】：选择鄂尔多斯盆地中南部张家滩页岩的64块岩芯样品,开展了有机碳和主、微量元素等地球化学测试工作。在分析其主、微量元素等地球化学特征的基础上,对张家滩页岩的古气候、古氧化还原条件和古生产力等古沉积环境进行了研究,讨论了控制鄂尔多斯盆地张家滩页岩有机质富集的主要因素。研究结果表明:张家滩页岩有机碳含量(TOC)较高,达2.14%~11.44%。与贫有机质页岩段相比,富有机质页岩段的Na_2O,CaO,U,V,Ba,Cu富集而Al_2O_3,TiO_2,K_2O,MgO含量低。古沉积环境指标表明张家滩页岩沉积时位温暖潮湿-半干旱的古气候,沉积底水氧化还原环境为贫氧-厌氧环境,表层水具有中—高的古生产力。有机质含量与氧化还原指标间的正相关关系表明,有机质含量主要受水体的氧化还原程度的控制,有机质富集属于"保存条件"模式。进一步研究显示,张家滩页岩有机质的富集主要是由古气候变化所造成湖水缺氧程度所控制。
[Abstract]:A total of 64 core samples from Zhangjiatan shale in the central and southern part of Ordos Basin were selected for geochemical testing of organic carbon, principal and trace elements. The paleoclimate, paleo-redox conditions and paleo-productivity of Zhangjiatan shale were studied. The main factors controlling the enrichment of organic matter in Zhangjiatan shale in Ordos Basin are discussed. The results show that the organic carbon content of Zhangjiatan shale is high, reaching 2.14 ~ 11.44. The Na _ 2O-CaOU _ (U) O _ (U) V _ (+) Ba _ (+) Cu in the organic shale segment is enriched and the content of MgO is low in Al _ (2) O _ (3) O _ (2) O _ (2) K _ 2O _ (2) O _ (2) O _ (2) O _ (2) O _ (2) O _ (2) O _ (2) O _ (2) O _ (2) O _ (2) O _ (2) O _ (. The positive correlation between the content of organic matter and the index of redox indicates that the content of organic matter is mainly controlled by the degree of redox. Further study shows that the enrichment of organic matter in Zhangjiatan shale is mainly controlled by the degree of anoxia in lake water caused by paleoclimate change.
【作者单位】：陕西延长石油(集团)有限责任公司研究院;陕西省页岩气勘探开发工程技术研究中心;中国科学院油气资源研究重点实验室中国科学院地质与地球物理研究所;中国科学院大学;中国石油长庆油田分公司勘探开发研究院;
【基金】：国家重大科技专项资助项目(2011ZX05008-004-72) 陕西省科技统筹创新工程计划资助项目(2012KTZB03-03-01-01)
【分类号】：P595;P618.13

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