摘要
中扬子中侏罗统主要散布于中扬子前陆盆地各次级盆地中,应用现代沉积学、高分辨率层序地层学理论,结合露头岩性、古生物、沉积相分析等手段,发现中侏罗统主要为辫状河、辫状河三角洲或扇三角洲以及滨浅湖沉积体系,在不同区域,分别以花家湖组、沙溪庙组和千佛崖组地层命名。不同区域层序特征既有差异,又存在相似性。根据高分辨率层序地层学理论,将花家湖组、沙溪庙组和千佛崖组分别划分为4个、4个和2个三级层序,局部地区还可细划四级层序,整个中侏罗统大致相当于1个二级层序。此层序地层格架的形成主要是受构造因素控制,即印支期以来中扬子地区发生强烈的构造变形和运动而形成复杂的盆山耦合体系,层序横向展布和纵向叠加于前陆盆地中。
The middle Jurassic System of the Middle Yangtze region is mainly distributed in some sub-basins of the Middle Yangtze foreland basin. This work is based on principles of modern sedimentology and high-resolution sequence stratigraphy in combination with analysis of outcrop lothology, pale- ontology and sedimentary facies. The result shows that this System is characterized by braided river, braided-river delta, fan delta, and shallow lake sedi- ments, and has named as the Huajiahu Formation, Shaximiao Formation and Qianfuya Formation for varied areas. Sequence stratigraphic characteristics of different regions exhibit both differences and similarities. Based on the theory of high-resolution sequence stratigraphy, the Huajiahu Formation, Shaximiao Formation and Qianfuya Formation can be respectively divided into 4,4 and 2 third-order sequences. Furthermore ,fourth-order sequences can be subdivi- ded in local areas. The whole Middle Jurassic System is roughly equivalent to a second-order sequence. The formation of this sequence stratigraphic frame- work is primarily controlled by the tectonic factors,i, e. the intensive tectonic deformation and movement since the Indosinian period, which resulted in a complicated basin-mountain coupling system that made the sequences distributed laterally and superimposed longitudinally in the foreland basin.
出处
《地质与勘探》
CAS
CSCD
北大核心
2012年第2期406-414,共9页
Geology and Exploration
基金
中国石油化工股份有限公司科技工程重点项目(编号QZ-2005-06)
国家自然科学基金(编号49803012和40472065)资助的成果
关键词
中扬子
中侏罗统
高分辨率
层序格架
构造控制
Middle Yangtze region, middle Jurassic, high-resolution, sequence framework, tectonic controls
