华北克拉通北缘寒武系层序地层划分

华北克拉通北缘寒武系碳酸盐岩作为区域油气勘探的重要目标，其沉积环境演化和层序地层格架的研究对区域地层及有利储层定位具有重要指导意义，也为华北地区寒武系油气勘探提供线索。以大量露头剖面实测分析为基础，结合典型井录井、测井、微观显微镜下分析以及地化测试等数据资料，在年代地层框架下进行旋回性地层分析研究，对华北克拉通北缘寒武系岩性、岩相以及地层叠置样式进行详细剖析，研究沉积趋势变化，总结寒武系层序地层划分样式。研究认为：在全球海平面变化控制下，华北地区自府君山组开始，发育广泛的由南向北的持续海侵，在陆源碎屑供给以及碳酸盐岩加积作用的相互制约下，华北地区表现为碳酸盐台地的形成-发展-镶边过程；以张夏组为界，中-下寒武统表现为缓坡-陆棚的沉积环境，上寒武统为具镶边的台地沉积背景；在不同层位不同层序边界类型（I型、Ⅱ型、Ⅲ型）的分隔作用下，将华北克拉通北缘寒武系划分为7个可区域性对比的三级层序，各三级层序高水位体系域多表现厚层清水碳酸盐岩沉积的特点，且受不同程度白云石化作用，成为区域寒武系重要的有利油气储集层。

Cambrian Sequence Stratigraphic Framework in Northern Margin of North China Craton

Cambrian carbonate rocks are key targets for regional oil and gas exploration in the northern margin of the North China craton. The study of sedimentary environment and sequence stratigraphic framework is meaningful to stratigraphic correlating and reservoir locating, it can provide clues for the Cambrian oil and gas exploration in North China. Based on outcrop and core observation, thin section analysis, microscope interpretation and geochemical analysis, the lithology, lithofacies and the stack mode of strata were studied, and the sedimentary trend and the division of sequence stratigraphy were discussed. The authors consider that a massive transgression was happened from south to north after Proterozoic in the northern margin of the North China craton, which was controlled by global eustatic sea level changes. Under the double restriction of clastic supply and carbonatite accretion, the North China craton experienced an evolution process of carbonate platform from being built, developed to rimmed. Bordered by Zhangxia Formation, the Lower-Middle Cambrian performed as a gentle slope-shelf environment, while the Upper Cambrian was a rimmed platform. The Cambrian strata in the northern margin of North China can be divided into 7 third-order sequences with different types of boundaries, which are regionally correlated. The most high level system tracts always form a thick-layer carbonate rocks, which are the most important oil and gas reservoirs.