松辽盆地红岗阶地青山口组地层层序和沉积特征

STRATIGRAPHIC SEQUENCES AND SEDIMENTARY FEATURES OF QINGSHANKOU FORMATION IN HONGGANG TERRACE

运用陆相层序地层学基本原理，在地震、测井和录井资料的综合分析基础上，将松辽盆地红岗阶地青山口组划分为3个三级层序，每个三级层序主要发育湖侵体系域和高位体系域，缺少低位体系域。青山口组3个三级层序对应着3个沉积旋回，发生了3次湖水进退，从整体上看是一个湖平面先上升后下降的沉积过程，SQ2的湖侵体系域沉积结束时湖水达到最深，SQ3的高位体系域沉积结束时湖水最浅。青山口组的沉积微相类型主要有水下分流河道、河口坝、前缘席状砂、前三角洲泥以及半深湖一深湖泥。

By adopting the basic principles of continental sequence stratigraphy, on the basis of the comprehensive analyses of the seismic, well logging and mud log data, Qingshankou Formation of Honggang Terrace area is divid- ed into three third-order sequences, and the lake-transgressive and highstand system tracts are each mainly devel- oped in third-order sequence, but the lowstand system tract is absent. The three sequences in Qingshankou Forma- tion is corresponded to three sedimentary cycles, and the inflow and outflow of the lake water occurred three times ; Overall, the sedimentary process of the lake level was first uplifted and then dropped, at the sedimentary end of the lake transgressive system tract in SQ2, the lake was the deepest ; on the contrary, the depth of the lake water at the sedimentary end of the highstand system tract in SQ3. The types of the sedimentary microfacies in Qingshankou For- mation are generally classified into underwater distributary channel, mouth bar, front sheet sand, predelta/prodeha mud and semideep-deep lake mud.