%0 Journal Article
%T 高分辨率层序地层划分在辫状河沉积相中的应用—以北京延庆硅化木国家地质公园剖面为例<br>Application of High-resolution Sequence Stratigraphy to Braided River Facies：Taking the Yanqing Silicified Wood National Geopark Section in Beijing as An Example
%A 吴鹏
%A 樊太亮
%A 王红亮&lt
%A br&gt
%A WU Peng
%A FAN Tailiang
%A WANG Hongliang
%J 现代地质
%D 2016
%X 摘要： 通过对延庆硅化木国家地质公园剖面的观察实测、剖面精细解剖及沉积观察描述，识别出了辫状河道、决口扇、泛滥平原三种辫状河沉积的微相类型，并分析了其沉积特征。利用高分辨率层序地层学的基准面旋回变化原理，在所测剖面中划分出了两个完整的中期旋回和多个构成中期旋回的短期旋回，在研究区建立了高分辨率层序地层格架。总结了辫状河野外露头基准面旋回转换面的两类识别标志：洪泛面及层序界面。洪泛面，包括河间潮湿泛滥平原泥岩发育段(需要具有一定厚度和分布范围)，河道之间叠置的决口扇(厚度较大处)及孤立的辫状河道层段。层序界面，包括泛滥平原泥岩段较少或不发育段，冲刷面之上具有相互叠置特征的河道沉积位置及在一定范围内具有可对比性且规模较大河道的位置。在低A/S比值条件下产生的横向上叠加成片、纵向上相互叠置的辫状河道砂体，其连通性相对较好，砂岩的厚度较大，泥质含量少，均质性较强，具有较强的可对比性。而在高A/S比值条件下产生的较少叠置或孤立河道砂岩，厚度较薄，横向上延伸范围有限，泥质含量高，可对比性较差。由此，初步形成了露头辫状河沉积相中高分辨率层序地层划分的方法，为辫状河沉积体系内高精度等时对比格架的建立、储层的识别与预测提供了依据。<br>Abstract: Through the observation and measurement on three braided river sedimentary outcrops of Yanqing Silicified Wood National Geopark Section in Beijing, three braided river microfacies of braided channel, floodplain and splay are been identified, and their sedimentary characteristics are analyzed. Two full medium-term cycles and some short cycles that constitute the medium-cycles are divided using the base-level cycles change principle of high-resolution sequence stratigraphy, and the stratigraphic framework is established. The cycle conversion surface identification of the braided river outcrop is summed up as the flooding surface and the sequence boundaries. Flooding surfaces include the wet floodplain shale development segments with a certain thickness and distribution, the splay stacked locations with a larger thickness and the isolated channel layers. Sequence boundaries include the locations with little or no development of flood plain mudstone, the locations of stacked river channel on the erosion surface and the positions of the river channel that can be correlated and has a big scale in a certain range. The braided channel sand bodies produced in low A/S ratio, are superimposed into a film horizontally and overlaid each other vertically, with good connectivity, big thickness, little mud, good heterogeneity and strong contractility. While the braided channel sand bodies that are produced in high A/S ratio, are isolated and less overlaid, with small thickness, limited range in horizon, high clay contain and poor connectivity. As a result, the high-resolution sequence stratigraphy of braided river facies is initially formed, which can provide the basis for the establishment of high accuracy correlation framework and the recognition and prediction of reservoir in outcrop braided river depositional system
%K 辫状河
%K 露头
%K 高分辨率层序地层
%K 基准面旋回
%K 沉积相
%K 延庆
%K braided river
%K outcrop
%K high-resolution sequence stratigraphy
%K base-level cycle
%K facies
%K Yanqing
%U http://www.geoscience.net.cn/CN/abstract/abstract13820.shtml