燕山地区宣龙坳陷长龙山组沉积相特征研究

Sedimentary facies in the Changlongshan Formation,Xuanlong depression,Yanshan area,Hebei

通过野外剖面观察和室内薄片、粒度分析及相标志的研究认为,长龙山期海侵范围急剧扩大,形成了一套成熟度较高的滨浅海相碎屑岩沉积,可划分为无障壁海岸和浅海陆棚两个相区。前者主要发育在长一段,可细分为前滨、临滨两种亚相;后者主要发育在长二段,以滨外陆棚沉积为主。提出了长龙山组的沉积相模式。

Two types of sedimentary facies may be classified, on the basis of field observation, thin-section examination, grain-size analysis and lithologic and sedimentary facies indicators, for the high-maturity littoral neritic clastic rocks in the Qingbaikouan Changlongshan Formation, Xuanlong depression, Yanshan area. They are the nonbarrier coast facies and neritic shelf facies. The former appears in the first member of the Changlongshan Formation, and may be subdivided into the foreshore and shoreface subfacies. The latter is organized in the second member of the Changlongshan Formation, and dominated by the offshore shelf deposits. The results of research in this study lead to the construction of the sedimentary facies model, and thus provide one useful approach to the improvement of the sedimentary facies analysis and prediction of the favourable reservoirs in the study area.