热水沉积岩岩石学特征:以内蒙古二连盆地白音查干凹陷下白垩统腾格尔组为例  

Petrological characteristics of hydrothermal-sedimentary rocks:A case study of the Lower Cretaceous Tengger Formation in the Baiyinchagan Sag of Erlian Basin,Inner Mongolia

作　　者：钟大康[1,2] 杨喆[1,2] 孙海涛[1,2] 张硕 Zhong Da-Kang1,2,Yang Zhe1,2 ,Sun Hai-Tao1,2, Zhang Shuo3(1 College of Geoscience, China University of Petroleum （Beijing） , Beijing 102249 ;2 State Key Laboratory of Petroleum Resources and Prospecting, China University of Petroleum （Beifiag） , Beijing 102249; 3 Resources Development Service Center of Bohai State-owned Assets, Tianjin 300202)

机构地区：[1]中国石油大学(北京)地球科学学院,北京102249 [2]中国石油大学(北京)油气资源与探测国家重点实验室,北京102249 [3]天津市渤海国资人才资源开发服务中心,天津300202

出　　处：《古地理学报》2018年第1期19-32,共14页Journal of Palaeogeography：Chinese Edition

基　　金：国家自然科学基金项目(编号:41472094;41302108)资助~~

摘　　要：内蒙古二连盆地白音查干凹陷下白垩统腾格尔组—都红木组发育1套热水沉积岩。通过岩心观察、显微镜下鉴定、扫描电镜、全岩X衍射和电子探针分析等手段,对研究区热水沉积岩的矿物组成、结构与构造特征、矿物组合关系进行系统研究,在此基础上进行岩石分类与命名。研究表明:研究区热水沉积岩在岩心上表现为深灰色、灰色和灰褐色;其矿物组分复杂多样,以白云石和沸石(钠沸石和方沸石)为主要造岩矿物,黄铁矿、菱镁矿、菱铁矿、水镁铁石及重晶石为次要矿物,混有黏土矿物、石英、钾长石和斜长石等泥质陆源碎屑;热水沉积岩结构构造特征复杂多样,根据结构特征可以划分为热水内碎屑结构、泥晶结构和团块结构3种,依据构造特征可以划分为纹层状和条带状构造、网脉状构造、同生变形构造、角砾状构造、蝌蚪状构造、星散状构造、块状构造和韵律性构造8种构造类型;以主要的热水沉积矿物白云石、沸石及陆源的泥质物(黏土矿物、石英及长石)为三端元,以90%、75%、50%、25%、10%为界限,将研究区热水沉积岩划分为泥质白云岩、含沸石白云质泥岩及沸石岩,前两者是研究区的主要岩石类型。本区热水沉积岩岩石学特征的研究可为其他地区的热水沉积岩及其沉积模式研究奠定基础,可以进一步丰富现今的沉积学理论。In the Baiyinchagan Sag of Erlian Basin,Inner Mongolia,there is a set of hydrothermalsedimentary rocks occurred in the Tengger Formation and Duhongmu Formation of the Lower Cretaceous. Inorder to classify hydrothermal-sedimentary rocks,the mineral compositions,textures,structures and mineral assemblages were analyzed by studying the drilling cores,microscopes,field emission scanning electron microscope（FE-SEM）,total rock X-ray diffraction, and electron probe analysis（EPMA）. The rocks are displayed dark-grey,grey and grey-brown colors. The mineral compositions of rocks are complex and diverse. Dolomite and zeolite（natrolite and analcime） are main rock-forming minerals,and pyrite,magnesite,siderite and barite are secondary minerals,which are mixed with muddy terrestrial sediments composed of clay minerals,quartz,and plagioclase. The textures of hydrothermal-sedimentary rocks can be divided into four types and structures can be divided into nine,which differentiate them from normal lacustrine depositions like carbonate and terrestrial clastic rocks. According to the contents of dolomite,zeolite and terrestrial sediment（marked by 90%,75%,50%,25% and 10%）,the hydrothermal-sedimentary rocks are generally divided into argillaceous dolostone,zeolite-bearing dolomitic mudstone and zeolite rock,of which the two formers are major types of hydrothermal-sedimentary rocks in study area. This research would provide an case study to analyze hydrothermal-sedimentary rocks and build depositional model in other basins,as well as enrich theoretical knowledge of sedimentology.

关 键 词：热水沉积岩 岩石学特征 分类与命名 白音查干凹陷 

分 类 号：P588.2[天文地球—岩石学]