徐家围子断陷“凹中隆”地质特征及其成因

松辽盆地深层徐家围子断陷的“凹中隆”构造与周围地层在沉积-构造特征上存在着明显的不同。为此,以地震、钻井及区域地质资料综合分析成果为基础,结合“凹中隆”所表现出的独特地质特征,从构造地层的角度,提出了“凹中隆”构造是早期古前陆型盆地在浅部开的一个“窗口”的认识。运用正断层相关褶皱的观点,将“凹中隆”的形成、发展及消亡成因机制分成5个阶段并进行了系统研究和论述。结果指出：“凹中隆”与其两侧断陷盆地形成时间相同,但分属不同时期的沉积地质体,是两期盆地的产物。这一认识为分析松辽盆地深部地层提供了全新的思路,也展示了深层天然气勘探的巨大潜力。

Geologic Features and Genesis of the "Intra-sag Uplift" in Xujiaweizi Fault Depression, the Songliao Basin

"Intra sag uplift" of Xujiaweizi fault depression in the Songliao basin is significantly different with the surrounding areas in respects of sedimentary structural features. Based on the comprehensive study of seismic, well and regional geologic data and in combination with the unique geologic features of the "intra sag uplift", it is believed that the "intra sag uplift" is a "window" opened in the shallow part of the early fossil foreland basin. Its formation, development and consumption are systematically discussed in 5 stages by using the theory of normal faults being associated with folds. Although the "intra sag uplift" is contemporaneous with the faulted basin on its both sides, they belong to different geologic bodies formed in different geologic time and are the products of basins in two stages. This provides a new understanding for exploration in deep of the Songliao basin and reveals the large deep gas potential in the study area.