鄂尔多斯盆地黄陵地区三叠系延长组长6浊积岩物源分析
来源期刊：中南大学学报(自然科学版)2013年第4期
论文作者：刘锦 冯娟萍 李文厚 郭艳琴
文章页码：1464 - 1471
关键词：鄂尔多斯盆地；浊积岩；长6油层组；岩石地球化学；重矿物；物源分析
Key words：Ordos Basin; turbidite; Chang 6 Formation; lithogeochemistry; heavy mineral; provenance analysis
摘 要：利用重矿物及其组合、砂岩碎屑组成和岩石地球化学等资料对鄂尔多斯盆地黄陵地区三叠系延长组长6浊积岩的物源进行研究，发现长6油层组总体上稀土总量为中等—较高，轻、重稀土分馏不明显，为铕微正异常的弱右倾稀土谱型；泥岩w(Nb)/w(Ta)，w(Th)/w(U)，w(La)/w(Sm)，w(Hf)/w(Th)和w(Gd)/w(Yb) (大部分大于2)等微量元素比值表明其与盆地东北缘造山带的太古界和元古界变质岩具有良好的亲缘性；浊积砂岩样品大部分落在隆升基底区域内。岩石地球化学特征、源区性质和构造背景共同表明，黄陵地区延长组长6浊积岩物源主要来自盆地东北部基底隆升的造山带。
Abstract: Based on lithogeochemistry, detrital composition of sandstone and other analysis methods, the source of Chang 6 Formation turbidite was studied carefully in Huangling area, Ordos Basin. It is shown that the ΣREE of Chang 6 mudstones are medium to high, fractional degree of HREE and LREE is not obvious and is of weakly right inclination and weakly positive europium abnormality of rare-earth pattern. Also, according to the analysis of the values of w(Nb)/w(Ta), w(Th)/w(U), w(La)/w(Sm), w(Hf)/w(Th) and w(Gb)/w(Yb) (most values are larger than 2) in Chang 6 mudstones, it is confirmed that Chang 6 mudstones and Archeozoic Proterozoic metamorphic rocks of orogenic belt in Northeastern Margin of Ordos Basin have a close relationship. The sandstone samples fall in the region of the basement uplift on the diagram. Through comprehensive analysis of the characteristics of lithogeochemistry, the nature of source area and the tectonic setting, the turbidite of Chang 6 Formation are mostly from the orogenic belt in Northeastern Margin of the Ordos Basin.
刘锦1, 2, 3，冯娟萍4，李文厚1，郭艳琴5
(1. 西北大学 地质学系，陕西 西安，710069；2. 中国科学院 地质与地球物理研究所，北京，100029；3. 胜利油田，鲁明公司，山东 东营，257000；4. 西安科技大学 地质与环境学院，陕西 西安，710054；5. 西安石油大学 油气资源学院，陕西 西安，710065)
摘 要：利用重矿物及其组合、砂岩碎屑组成和岩石地球化学等资料对鄂尔多斯盆地黄陵地区三叠系延长组长6浊积岩的物源进行研究，发现长6油层组总体上稀土总量为中等—较高，轻、重稀土分馏不明显，为铕微正异常的弱右倾稀土谱型；泥岩w(Nb)/w(Ta)，w(Th)/w(U)，w(La)/w(Sm)，w(Hf)/w(Th)和w(Gd)/w(Yb) (大部分大于2)等微量元素比值表明其与盆地东北缘造山带的太古界和元古界变质岩具有良好的亲缘性；浊积砂岩样品大部分落在隆升基底区域内。岩石地球化学特征、源区性质和构造背景共同表明，黄陵地区延长组长6浊积岩物源主要来自盆地东北部基底隆升的造山带。
关键词：鄂尔多斯盆地；浊积岩；长6油层组；岩石地球化学；重矿物；物源分析
LIU Jin1, 2, 3, FENG Juanping4, LI Wenhou1, GUO Yanqin5
(1. Department of Geology, Northwest University, Xi’an 710069, China;2. Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100029, China;3. Luming Oil and Gas Co. Ltd., Shengli Oilfield, Dongying 257000, China;4. College of Geology and Environment, Xi’an University of Science and Technology, Xi’an 710054, China;5. Institute of Oil and Gas Resources, Xi’an Shiyou University, Xi’an 710065, China)
Abstract:Based on lithogeochemistry, detrital composition of sandstone and other analysis methods, the source of Chang 6 Formation turbidite was studied carefully in Huangling area, Ordos Basin. It is shown that the ΣREE of Chang 6 mudstones are medium to high, fractional degree of HREE and LREE is not obvious and is of weakly right inclination and weakly positive europium abnormality of rare-earth pattern. Also, according to the analysis of the values of w(Nb)/w(Ta), w(Th)/w(U), w(La)/w(Sm), w(Hf)/w(Th) and w(Gb)/w(Yb) (most values are larger than 2) in Chang 6 mudstones, it is confirmed that Chang 6 mudstones and Archeozoic Proterozoic metamorphic rocks of orogenic belt in Northeastern Margin of Ordos Basin have a close relationship. The sandstone samples fall in the region of the basement uplift on the diagram. Through comprehensive analysis of the characteristics of lithogeochemistry, the nature of source area and the tectonic setting, the turbidite of Chang 6 Formation are mostly from the orogenic belt in Northeastern Margin of the Ordos Basin.
Key words:Ordos Basin; turbidite; Chang 6 Formation; lithogeochemistry; heavy mineral; provenance analysis
