冀中地区早第三纪沉积岩化学元素分布特征及其多元统计研究

THE DISTRIBUTIVE FEATURES OF CHEMICAL ELEMENTS OF PALEOGENE SEDIMENTARY ROCKS IN THE CENTRAL PART OF HEBEI PROVINCE AND THE STUDY BY USING MULTI-ELEMENT ANALYTICAL METHOD

在冀中地区油气勘探所钻的3口井剖面中，系统选取早第三纪沉积岩岩屑样品。基本上2m取一个样，3口井样品总数约3500个。每个样品用光谱定量分析11种化学元素：Ca、Mg、Ti、Ba、Mn、Zr、V、Cr、Pb、Cu、Ni。应用计算机技术和多元分析方法，经过综合研究查明了冀中地区下第三系砂岩、泥岩和不同颜色泥岩化学元素的分布特征。早第三纪各组段地层元素分布不同，其纵向上的变化界线与地质上分层界线基本吻合，是地层划分对比的一个依据。用对应分析方法研究岩石化学资料。，可以查明元素之间、元素与样品之间以及样品与样品之间的关系和规律性。研究表明Ba、Mn、Zr、Pb的关系密切，属于亲碎屑元素；Ti、Cr、V、Ni、Cu的关系密切，属于亲粘土元素；Ca、Mg、Ti的关系密切，属于亲碳酸盐元素。96井主因子F1、F2累计方差达95％，F1、F2主因子主要由Ca、Mg、Ti三元素所决定。F1突出地反映灰质沉积等地球化学作用，F2突出地反映机械沉积作用。主因子F1和F2在纵向上的周期性变化反映了沉积作物的旋回特征，样品在F1－F2因子平面上规律性地展布反映了沉积相特征，96井下第三系地球化学－沉积相图概括了主要的研究成果。

Among the cross-sections of three wells drilled in Jizhong area, cutting samples of early Tertiary sedimentary rocks are systematically taken, generally every 2 meters with a total number of samples of 3500. Each sample is quantitatively analyzed with spectrographic method for 11 ele-ments; Ca,Mg,Ti,Ba,Mn,Zr,V,Cr,Pb,Cu,Vi. By using computer and multi-elemental analytical methods, the distributive features of chemical elements for Paleogene sandstone, mudstone and multi-colored mudstones in Jizhong area are well defined. The element distribution differs from one interval to another in early Tertiary, which generally match vertically with geological zonation markers, being a basis for stratigraphic zonation boundaries. The relationship between elements, elements and samples , and between samples could be defined by using correlative analyticalmethod. It is indicated by the study that Ba,Mn,Zr and Pb have close relations, belonging to philo-clastic elements, where Ti,Cr,V, Ni and Cu belonging to philoclay elements, and Ca and Mg belonging to philocarbonates elements. The main factors F1 ,F2 in well 96 reaches 95%. The main factors F1 and F2 are determined principally by Ca, Mg and Ti. F1 reflects evidently the geochemical effect of limestone deposition and F2 reflects the mechanical deposition. The vertical regular changes of F1 and F2 reflect the depositional cycles. The regular distribution of samples on F1 and F2 surface reflects the feature of depositional facies. The geochemical-depositional facies map of Tertiary for Well 96 is the summary of the research results.