渤海湾盆地上古生界泥岩地球化学特征  

Geochemical characteristics of Upper Paleozoic mudstone in BohaiBay Basin

作　　者：侯中帅 陈世悦 桑树勋[3] 林会喜[4] 楼达[5] HOU Zhongshuai;CHEN Shiyue;SANG Shuxun;LIN Huixi;LOU Da(Key Laboratory of Deep Oil and Gas,Qingdao 266580,China;School of Geosciences,China University of Petroleum (East China),Qingdao 266580,China;School of Resource and Geoscience,China University of Mining and Technology,Xuzhou 221116,China;Research Institute of Petroleum Exploration and Development,Shengli Oilfield Company,SINOPEC,Dongying 257015,China;PetroChina Dagang Oilfield Company,Tianjin 300280,China)

机构地区：[1]深层油气重点实验室,山东青岛266580 [2]中国石油大学(华东)地球科学与技术学院,山东青岛266580 [3]中国矿业大学资源与地球科学学院,江苏徐州221116 [4]中国石化胜利油田勘探开发研究院,山东东营257015 [5]中石油大港油田公司,天津300280

出　　处：《煤炭学报》2020年第4期1457-1472,共16页Journal of China Coal Society

基　　金：国家油气重大专项资助项目(2016ZX05006-007)。

摘　　要：为了明确渤海湾盆地上古生界泥岩中微量元素及稀土元素的特征及其地质意义,应用电感耦合等离子质谱法对渤海湾盆地36个泥岩样品的微量元素及稀土元素进行测试,同时结合露头、岩芯、薄片、全岩X射线衍射和黏土矿物X射线衍射等观察分析,对研究区上古生界泥岩的发育特征、岩石成分、微量元素和稀土元素参数和空间分布规律、沉积水体的古盐度、物源区特征、沉积速率和层序地层意义进行了探讨。研究表明:渤海湾盆地上古生界泥岩微量元素含量与上地壳相似,稀土元素相对富集,轻重稀土间分异特征明显;杂色泥岩遭受了风化淋滤作用的改造,岩性为铝土岩或铝土质泥岩,岩石中的微量元素和稀土元素发生了活化迁移导致参数表现出异常值,沉积时的元素信息已被破坏;从本溪组到山西组,泥岩中稀土元素含量不断升高,下石盒子组较山西组降低,从下石盒子组到上石盒子组奎山段,泥岩中稀土元素含量逐渐升高;Sr/Ba比值反映了晚古生代海侵作用由发展到衰退的过程以及间歇性的海泛作用;物源区构造背景具有活动大陆边缘的特征,岩性以沉积岩、花岗岩和碱性玄武岩为主,地层时代具有先变老后变新的特点;沉积速率由本溪组至上石盒子组奎山段逐渐升高;下石盒子组顶部杂色泥岩中微量元素Sc,Co,Ni,Rb,Sr,Ba含量和∑REE表现出异常低值,反映了大面积的沉积间歇作用,其顶面可以作为层序界面。In order to clarify the characteristics of trace elements and rare earth elements(REEs)in the Upper Paleozoic mudstones of the Bohai Bay basin and their geological significance,combined with outcrop,core and thin section observation,whole rock X-ray diffraction and clay mineral X-ray diffraction analysis,the trace elements and REEs in 36 mudstone samples from Bohai Bay basin were determined by inductively couple-plasma mass spectrometry(ICP-MS).The development characteristics and composition,geochemical parameters and spatial distribution of trace elements and REEs of Upper Paleozoic mudstones,paleo-salinity,the characteristics of provenance,deposition rate and the significance of sequence stratigraphy were discussed.The results show that the contents of trace elements in the Upper Paleozoic mudstones in Bohai Bay basin are similar to that of the upper crust,the REEs are relatively enriched and the differences between light and heavy REEs are obvious.The variegated mudstones have undergone the reworking of weathering and leaching and are composed of bauxite or bauxitic mudstone,the activation and migration of trace elements and REEs result in outliers in the parameters,therefore,the element information during deposition has been destroyed.From the Benxi formation to the Shanxi formation,the REEs contents in mudstone continuously increase.The REEs contents of the Lower Shihezi formation are lower than that of the Shanxi formation,and from the Lower Shihezi formation to the Kuishan member of the Upper Shishanzi formation,the REEs contents gradually increase.The Sr/Ba values reflect the process of transgression from development to decline and intermittent marine-flooding in Late Paleozoic.The tectonic setting of provenance area has the characteristics of active continental margin,the lithologies are dominated by sedimentary rocks,granite and alkaline basalt,and the stratigraphic ages have the characteristic of getting old first and then getting new.The deposition rate increases gradually from the Benxi formation to

关 键 词：微量元素 稀土元素 物质来源 层序界面 上古生界 

分 类 号：P595[天文地球—地球化学]