Based on outcrop, drilling, logging, geochemical analysis and seismic data, the karst landform and distribution of Permian volcanic rocks at the end of the sedimentary period of the Maokou Formation in the western Sichuan Basin are examined, and their petroleum geological significance is discussed. Affected by normal faults formed in the early magmatic activities and extension tectonic background in the late sedimentary period of the Maokou Formation, a local karst shallow depression under the background of karst slope came up in the Jianyang area of the western Sichuan Basin, where the residual thickness of the Maokou Formation was thinner. Basic volcanic rocks like pyroclastic rock of eruptive facies, basalt of overflow facies, diabase porphyrite of intrusive facies and sedimentary tuff of volcanic sedimentary facies were formed after karstification. However, under the effects of faulting and karst paleogeomorphology, the volcanic rocks in different areas had different accumulation features. In the Jianyang area, with long eruption time, the volcanic rocks were thick and complex in lithology, and accumulated in the karst depressions. In the Zhongjiang-Santai area located in the karst slope, there’s no fault developed, only thin layers of basalt and sedimentary tuff turned up. The karst landform controls the build-up of thick explosive facies volcanic rocks and also the development of karst reservoirs in the Maokou Formation, and the western Sichuan area has oil and gas exploration potential in volcanic rocks and the Maokou Formation.

基于露头、钻井、测井、地球化学分析和地震资料，研究了川西茅口组沉积期末二叠系火山岩岩溶地貌和分布，探讨了其石油地质意义。受茅口组沉积晚期早期岩浆活动形成的正断层和伸展构造背景的影响，四川盆地西部简阳地区出现岩溶斜坡背景下的局部岩溶浅坳陷。茅口组厚度较薄。喷发相火山碎屑岩、溢流相玄武岩等基性火山岩，岩溶作用形成侵入相辉绿岩和火山沉积相沉积凝灰岩。但在断裂和岩溶古地貌的作用下，不同地区的火山岩具有不同的成藏特征。简阳地区喷发时间长，火山岩厚、岩性复杂，堆积于岩溶洼地。位于岩溶斜坡的中江-三台地区，不发育断层，仅出现薄层玄武岩和沉积凝灰岩。岩溶地貌控制着茅口组稠密爆炸相火山岩的形成和岩溶储集层的发育，川西地区火山岩和茅口组具有油气勘探潜力。在断裂和岩溶古地貌的作用下，不同地区的火山岩具有不同的成藏特征。简阳地区喷发时间长，火山岩厚、岩性复杂，堆积于岩溶洼地。位于岩溶斜坡的中江-三台地区，不发育断层，仅出现薄层玄武岩和沉积凝灰岩。岩溶地貌控制着茅口组稠密爆炸相火山岩的形成和岩溶储集层的发育，川西地区火山岩和茅口组具有油气勘探潜力。在断裂和岩溶古地貌的作用下，不同地区的火山岩具有不同的成藏特征。简阳地区喷发时间长，火山岩厚、岩性复杂，堆积于岩溶洼地。位于岩溶斜坡的中江-三台地区，不发育断层，仅出现薄层玄武岩和沉积凝灰岩。岩溶地貌控制着茅口组稠密爆炸相火山岩的形成和岩溶储集层的发育，川西地区火山岩和茅口组具有油气勘探潜力。火山岩厚而复杂，堆积于岩溶洼地。位于岩溶斜坡的中江-三台地区，不发育断层，仅出现薄层玄武岩和沉积凝灰岩。岩溶地貌控制着茅口组稠密爆炸相火山岩的形成和岩溶储集层的发育，川西地区火山岩和茅口组具有油气勘探潜力。火山岩厚而复杂，堆积于岩溶洼地。位于岩溶斜坡的中江-三台地区，不发育断层，仅出现薄层玄武岩和沉积凝灰岩。岩溶地貌控制着茅口组稠密爆炸相火山岩的形成和岩溶储集层的发育，川西地区火山岩和茅口组具有油气勘探潜力。