Abstract: Based on areal geologic background, integral analysis on core observation, particle size analysis, and logging curve shape indicates that the fourth section of Quantou formation in Liangjing Gudian area is of delta-front and shore shallow lacustrine depositional systems. Two major river systems which come from southeast and southwest supply the source materials to this area. Especially, the microfacies of delta plain mainly developes subwater distributary channels,its flank, subwater interdistributary bay, and the delta front mainly consist of interchannels, debouch bars, far bars and mat shape sands. In this area, the distributary channel constitutes the dominated reservoirs. The research result firstly explains the sedimentary microfacies' space-time distributing characters, and provides geologic base for the further exploration and development.

Key words: sedimentary microfacies, provenance analysis, fourth section of Quantou formation, Songliao basin

摘要： 从区域地质背景出发，通过岩芯观察、粒度分析、重矿物以及测井曲线形态等资料的综合分析表明，两井孤店地区泉头组四段主要为三角洲前缘-滨浅湖沉积体系，来自东南和西南的两大水系同时对该区供应沉积物源。三角洲水下平原主要发育水下分流河道、水下分流间湾、水下分流河道侧翼等沉积微相；前缘部位发育河口坝、坝间、远砂坝、席状砂等，水下分流河道是本区占主导地位的骨架砂体。首次指出了该区泉四段不同时期各相带的空间组合及分布特征，为本区泉四段今后的油气勘探和开发提供了依据。

关键词: 沉积微相, 物源分析, 泉四段, 松辽盆地