摘要
主要根据野外露头资料、钻井岩芯和测井资料,对川东地区须家河组岩石特征、剖面结构和沉积环境进行了详细研究,首次发现了舌形贝化石,确定川东须家河组底部发育海相沉积,并在须家河组内部发现砾岩层和角度不整合面,确定安县运动对川东须家河组沉积有很大影响。从须家河组沉积前四川盆地古地貌特征、须家河组沉积初期古地理面貌、沉积构造、古生物特征及关键性层序界面等多个方面论证了川东地区发育须一段沉积,同时根据须家河组顶、底及内部不整合3个关键界面对川东须家河组进行了层序地层划分和区域地层对比,认为川东地区须家河组发育须一段~须六段6个相对完整的岩性段:须一段主要为一套有障壁海岸的瀉湖-潮坪或海湾沉积,须二段~须六段主要为辫状河三角洲沉积,其中须三段及须五段仍以细、中砂岩为主,这一特征有别于广安及龙岗等靠近盆地的其他区域,但正好反映了陆相三角洲沉积体系从盆地边缘到盆地中央砂岩逐渐减少的一般规律。
Based on outcrop, drilling core, and well log data, the stratigraphy and sedimentary environ- ments of the Early Triassic Xujiahe Formation in eastern Sichuan Province were analyzed. We report for the first time lingulid fossils from the Xujiahe Formation in eastern Sichuan Basin, suggesting a marine sedimentary facies for this stratigraphic unit. We also report a gravel layer and an angular unconformity within the Xujiahe Formation, suggesting that the Anxian Movement may have had an impact on the sedi- mentation of the Xujiahe Formation. Based on paleogeomorphic analysis, sedimentary structures, and pal- eontological data, it is demonstrated that the First Member of the Xujiahe Formation is well developed in eastern Sichuan Basin. Three unconformities, at the base and top and within the Xujiahe Formation, have been recognized. The Xujiahe Formation in eastern Sichuan can be divided into six members （First to Sixth Member ）. The First Member of the Xujiahe Formation is characterized by lagoonal-tidal flat coastal barrier or gulf dep delta deposits sedimentary e an and Longg and fewer san
出处
《地层学杂志》
CSCD
北大核心
2017年第1期94-102,共9页
Journal of Stratigraphy
基金
国家科技重大专项"四川盆地岩性油气藏富集规律与目标评价(编号:2011ZX05001-005)"
国家自然科学青年基金"川中地区须家河组砂岩中自生绿泥石成分演化及其地质意义(编号:41402085)"部分研究成果
关键词
岩石地层
地层对比
不整合
安县运动
须家河组
香溪群
三叠系
川东地区
lithostratigraphy, stratigraphic correlation, unconformity,Anxian Movement, Xujiahe Formation, Xiangxi Group, Triassic, Sichuan Basin
