关键词: 松辽盆地, 徐家围子断陷, 火山岩旋回, 火山岩测井特征

Abstract: The volcanic rocks of the Yingcheng formation in the Songliao Basin were formed by multiple and intermittent eruptions. Based on the core drilling data, the high-resolution volcanic cycles of the first member of Yingcheng formation in Xujiaweizi fault depression were divided, the volcanic cycle model were built, and the well logging characteristics of different lithology and lithofacies were summarized. The results reveal that, the first member of Yingcheng formation could be divided into 3 volcanic cycles, from the top to the bottom of each cycle, the values of gamma-ray and resistivity were higher and higher, the amplitude and frequency of the well logs in the interface of different cycles changed greatly, indicating the existence of the weathering crust or the sedimentary layer. Logging data of gamma-ray, resistivity and density were considered to be more sensitive in recognition of different volcanic lithology and lithofacies.

Key words: Songliao basin, Xujiaweizi fault depression, volcanic cycles, logging characteristics of volcanic rocks