摘要
四川盆地东北部元坝地区二叠纪-三叠纪沉积环境主要与北部广旺海槽形成与关闭、米仓山与大巴山隆起及二叠纪峨眉山玄武岩喷发有关。通过野外露头、三维地震数据、钻井资料的综合研究,认为长兴组-飞仙关组沉积为碳酸盐台地沉积体系,可进一步划分为台地蒸发岩、局限台地、开阔台地、台地边缘生物礁滩和台地边缘斜坡5个相带。长兴期沿台地边缘发育了台地边缘礁滩;飞一段早期相对平静,沉积末期广旺海槽全部关闭;飞二段至飞三段早期主要为开阔台地沉积;飞三段晚期-飞四段演变为局限台地-台地蒸发岩相。飞二段浅滩与长兴期礁滩大致处于相同位置,未发生侧向迁移;飞三段台内浅滩的发育有明显的侧向迁移和垂向叠置的特征;从西南向东北方向,飞仙关组早期台地沉积区向陆棚沉积区迁移。
The depositional environment of Permian and Triassic in the Yuanba area in the northeast of Sichuan Basin is mainly in connection with the formation and closing of Guangwang ocean trough in the north, the uplift of Micang Mountain and Daba Mountain, and the Emeishan Basalt eruption of Permian. The depositional system of the Upper Permian Changxing Formation and Lower Triassic Feixianguan Formation is a carbonate platform which can be classified into five facies, that is, platform evaporite, restricted platform, open platform, platform edge reef and platform edge slope. According to the research for the outcrop in Northeast Sichuan, the 3-D seismic data obtained from the Yuanba area, the completion and drilling information in the work area and vicinities synthetically, the authors conclude that the platform edge reef develops along the platform edge in the Changxing period. The early Member 1 of Feixianguan Formation was relatively calm and the Guangyuan-Wangcang ocean trough was closed completely in the last deposition stage. The deposition of the early Member 2 to Member 3 was mainly open platforms. The deposition of the late Member 3 to Member 4 evolved to, restricted platforms and platform evaporite. The shallows of Member 2 and the reef of the Changxing period at the same place generally didnot migrate sideways. There are obvious features with sideway migration and vertical superposition in the shallows of Member 3. The platform sediment trap in the early Feixianguan Formation migrated to the continental shelf sediment trap from southwest to northeast.
出处
《成都理工大学学报（自然科学版）》
CAS
CSCD
北大核心
2008年第6期663-668,共6页
Journal of Chengdu University of Technology: Science & Technology Edition
基金
国家重大基础研究(973)项目(2005CB422105)
关键词
川东北
元坝地区
长兴组
飞仙关组
碳酸盐岩台地
沉积体系
Northeast Sichuan
Yuanba
Changxing Formation
Feixianguan Formation
carbonate platform
depositional system
