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徐家围子断陷位于松辽盆地北部的东南断陷区,断陷形成于晚侏罗世到早白垩世早期,中生代火成岩较为发育,主要目的层段为营城组一段。在钻井取心研究基础上,根据火山岩的岩性、电性及地震反射特征,对研究区火山岩旋回和期次进行了划分与对比,建立了营城组火山岩旋回、期次模式,总结了旋回、期次的岩心标志、测井响应标志及地震反射标志。通过对研究区火山岩旋回、期次的对比发现,研究区营城组一段发育4个喷发旋回,旋回Ⅰ为中基性岩浆喷发,规模小,旋回Ⅱ为流纹质酸性熔浆喷发,局部可见少量安山岩,火山岩发育厚度和范围比旋回Ⅰ都有明显的增大,旋回Ⅲ为流纹质的酸性岩浆喷发,是本区火山喷发活动的高潮期,旋回Ⅳ以沉火山碎屑岩为主。通过对研究区火山岩地层的划分与对比,为下一步的火山岩勘探开发工作奠定了基础。
The Xujiaweizi Fault Depression is located in the southeast of the Songliao Basin. The faulted depression formed between the Late Jurassic and early Early Cretaceous. The Mesozoic igneous rocks developed well and the main target interval was the first segment of Yingcheng Formation. Based on the drilling coring research, according to the lithology, electrical properties and seismic reflection characteristics of volcanic rocks, the cycle and period of volcanic rocks in the study area are divided and contrasted, and the cycle and period modes of volcanic rocks in Yingcheng Formation are established. The cycle , Core rock marks, log response marks and seismic reflection marks. By comparing the volcanic cycles in the study area with those in the study area, it is found that there are four eruption cycles in the first stage of Yingcheng Formation in the study area. The cycle I is a mafic magmatic eruption with a small scale. The rotation II is a sliver acidic melt eruption, It can be seen that a small amount of andesite and volcanic rock have a larger thickness and range than that of the volcanic rock Ⅰ. The spin Ⅲ is rhyolitic acidic magma eruption, which is the climax of volcanic eruption activity in this area. . The division and contrast of volcanic strata in the study area laid the foundation for the next volcanic exploration and development.