天然气工业2024，Vol.44Issue(3)：72-86,15.DOI:10.3787/j.issn.1000-0976.2024.03.006
四川盆地中部地区中侏罗统物源体系格局及时空演化
Pattern and spatiotemporal evolution of the Middle Jurassic provenance system in central Sichuan Basin
摘要
Abstract
The Middle Jurassic Shaximiao Formation in central Sichuan Basin is an important tight gas exploration battlefield in China,and its provenance system and source rocks are complex and variable,which restricts the subsequent oil and gas exploration to a certain extent.Based on the analysis of detrital components,elemental geochemistry,and zircon clastic composition of each sub-member of the Shaximiao Formation,the debris content,source rock properties,and structural setting of the Shaximiao Formation are investigated to explore the controlling effects of source rocks and tectonesm of orogenic belt on the provenance system.The results show that the Shaximiao Formation in the western part of central Sichuan Basin has greatly varying single-crystal quartz content,and significant change in the compositional maturity of the sandstone in the plane and vertical direction;in the northwestern part,which rests in an integrated tectonic environment with island arcs,mixed orogenic belts,and collisional orogenic belts,the source rocks are mainly upper crustal felsic rocks and intermediate-acid mixed igneous rocks,the tectonic setting is dominated by continental island arcs,as well as active continental margins,which presents a high coupling to the Shaximiao Formation source rocks in the northern part;a high coupling is also found between the southwestern part and the western Sichuan Basin and southern section of Longmen Mountain;and the zircon age spectrum of the Shaximiao Formation in the eastern part is well coupled with that in eastern Sichuan Basin.During J2s1 and J2s21,the northern part of central Sichuan Basin formed the primary pattern of long-axis material supply as a result of Daba Mountain reverse thrust,while the southwestern part of central Sichuan Basin experienced short-axis transport from the southern section of Longmen Mountain.During J2s22 and J2s23,the strong over thrusting of Daba Mountain caused the entire central Sichuan Basin to be filled with long-axis distal deposits.During J2ss24,the thrusting in the northern section of Longmen Mountain provided material supply to the northwestern part of central Sichuan Basin,but the main part of central Sichuan Basin was dominated by the Daba Mountain province system.The study results provide a theoretical reference for reconstructing the paleogeography and predicting favorable sand bodies in the Middle Jurassic in the Sichuan Basin.关键词
四川盆地中部地区/中侏罗统沙溪庙组/碎屑分析/元素化学分析/构造作用/物源分析Key words
Central Sichuan Basin/Middle Jurassic Shaximiao Formation/Clastic analysis/Elemental chemical analysis/Tectonism/Provenance analysis分类
能源科技引用本文复制引用
赵晓明,胡成军,肖尧,葛家旺,杨长城,冯潇飞,宋林珂,肖红林,吴鑫涛..四川盆地中部地区中侏罗统物源体系格局及时空演化[J].天然气工业,2024,44(3):72-86,15.基金项目
国家自然科学基金项目"盐底辟触发型块体搬运沉积:构型样式及控制因素"(编号:42072183)、四川省自然科学基金项目"南海琼东南陆缘第四纪高频层序地层构型、时空差异及主控因素"(编号:2023NSFSC0810). （编号:42072183）
