【摘要】 中奥陶统马家沟组为一套海相碳酸盐岩地层.豫北东姚一带马家沟组出露较全,分布稳定,是进行马家沟组层序地层研究的有利地区.在系统研究野外实测剖面的基础上,根据8个岩性段的岩石组合特征、垂向变化规律,在区内马家沟组中识别出2个Ⅰ型层序界面和5个Ⅱ型层序界面,划分出1个二级层序和6个三级层序.通过讨论和分析该区马家沟组各级层序的特征,建立了东姚一带马家沟组的层序地层格架.结合层序地层特征分析,认为区内马家沟组的沉积环境经历了6次海进海退旋回.对区内中奥陶统马家沟组的层序地层研究,可以为研究豫北地区古生代的海平面变化提供参考.更多还原

【Abstract】 The Middle Ordovician Majiagou Formation is a set of marine carbonate rock strata. The formation is developed completely with stable distribution in Dongyao area of northern Henan Province,a favorable area to study the sequence stratigraphy. Based on the systematic study of surveyed profiles,with the rock assemblage and vertical variation rules of 8 lithologic members,two Type I and five Type II sequence boundaries are identified in the formation,which is further divided into 1 second-order sequence and 6 third-order sequences. The sequence stratigraphic framework of Majiagou Formation in Dongyao area is established by analyzing the characteristics of each order sequence.According to the features of sequence stratigraphy,it is believed that the sedimentary environment of Majiagou Formation in the area has undergone 6 transgressive and regressive cycles. The study can provide a reference for research of the Paleozoic sea level change in northern Henan Province.更多还原