华北地台东部中奥陶世岩相古地理特征

发布时间：2019-02-15 22:59

【摘要】：以明确华北地台中奥陶世沉积格局分布及演化特征为目的,基于层序地层学理论,将华北地台东部中奥陶统划分为5个三级层序,并以三级层序为单位进行沉积相分析和岩相古地理编图。从层序地层的等时性出发,研究了本区中奥陶世岩相古地理特征。华北地台东部中奥陶世以持续海侵为主,层序地层的发展受海侵规模、时间及短暂海退的影响,中部地层发育最为齐全。古地理格局总体上表现为南北高、中间低,早期至晚期演化具有一定的继承性和明显的发展性。古地理环境受构造和海平面变化综合作用的影响,随着海侵扩大,云坪沉积减少,局限台地和开阔台地占据绝对优势。各期沉积相的分布格局有所差异,但整体而言,继承性明显,南北两侧的隆升格局造成南北分化显著,沉积相带南北对称,开阔台地常为南北两侧的局限台地所夹持,反映了构造隆升背景下沉积环境对海平面变化的敏感性。沉积过程的多旋回性和岩性组合的韵律性使得中奥陶统形成了多套有利的生储盖组合,中新生界保存条件较好的渤海湾盆地区为有利勘探区。
[Abstract]:In order to clarify the distribution and evolution characteristics of sedimentary pattern in the Middle Ordovician in the North China platform, the Middle Ordovician in the eastern part of the North China platform is divided into five third-order sequences based on sequence stratigraphy theory. Sedimentary facies analysis and lithofacies paleogeography mapping are carried out in the third order sequence. Based on the isochronicity of sequence stratigraphy, the lithofacies and paleogeography of middle Ordovician in this area are studied. The Middle Ordovician transgression dominated in the eastern part of the North China platform. The development of sequence stratigraphy is affected by the transgression scale, time and temporary regression, and the central stratigraphy is the most complete. The paleogeographic pattern is generally high in the north and south and low in the middle. The evolution from the early to the late period has a certain inheritance and obvious development. The paleogeographic environment is affected by tectonic and sea level changes. With the expansion of transgression, the Yunping sediments decrease, and the confined and open platforms occupy the absolute advantage. The distribution pattern of sedimentary facies varies from stage to stage, but on the whole, the inheritance is obvious. The uplift pattern on both sides of the north and south causes the differentiation between the north and the south, and the sedimentary facies belt is symmetrical to the north and south, and the open platform is often held by the limited platform on both sides of the north and south. It reflects the sensitivity of sedimentary environment to sea level change in tectonic uplift background. The polycyclicity of the sedimentary process and the rhythm of the lithologic assemblage have led to the formation of several favorable assemblages of the source reservoirs and caprocks in the Middle Ordovician and the favorable exploration area in the Bohai Bay Basin where the Mesozoic and Cenozoic strata are well preserved.
【作者单位】：山东科技大学地球科学与工程学院;
【基金】：国家自然科学基金面上项目“沁水盆地煤层气与致密砂岩气共生成藏机理研究”(41172108) 国家重大专项“十三五”课题“中深层煤系地层立体勘探有利目标优选”(2016ZX05041005)和“岩性地层油气藏区带、圈闭评价方法与关键技术”(2016ZX05001003)联合资助
【分类号】：P618.13;P534.42

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