川西前陆盆地上侏罗统蓬莱镇组沉积特征  

The Characteristics of Sedimentary Facies at Penglai Town Formation of Upper Jurassic in Western Sichuan Foreland Basin

作　　者：陈兆荣[1] 侯明才[1] 董桂玉[1] 谭万仓[1] 万梨[2] 

机构地区：[1]成都理工大学沉积地质研究院,四川成都610059 [2]中国石化勘探南方分公司,四川成都610041

出　　处：《东华理工大学学报（自然科学版）》2008年第4期325-331,共7页Journal of East China University of Technology(Natural Science)

摘　　要：经岩性、岩石组合、沉积韵律等综合分析认为川西前陆盆地上侏罗统蓬莱镇组主要为冲积扇、曲流河、三角洲和湖泊沉积。其中冲积扇发育扇中和扇端两个亚相,扇根不发育;曲流河发育河道和洪泛平原两个亚相;三角洲发育三角洲平原、三角洲前缘以及前三角洲三个亚相;而湖泊相主要发育滨浅湖和半深湖沉积,深湖在研究区内不发育。在龙门山前缘的盆地边缘发育冲积扇相带,大小不同的冲积扇体连接或叠覆构成冲积扇群。并依次出现扇中、扇端的微相分带,同时砾石由粗变细,逐渐过渡到河流的砂岩相;由河流往东则进入湖泊沉积区,并在河流入湖处形成三角洲相沉积。根据冲积扇—曲流河—三角洲—湖泊的时空展布规律,建立了本区蓬莱镇组的沉积模式。The Penglai town formation of Upper Jurassic in Western Sichuan foreland basin is regarded as mainly deposited in the environment of alluvial fan, meandering river, delta and lake by analyzing lithologic characters, rock association and sedimentary rhythm. The middle fan and fan apex of the alluvial fan are developed well, and the lower part of alluvial fan is undeveloped. Meandering river develops channel and flood plain. Delta develops delta plain, delta front and prodelta. The lacustrine facies develops shore-lacustrine deposit and semi-deep lacustrine deposit, and the deep lacustrine deposit is undeveloped in the studying area. At the basin fringe area of the frontal of Longmenshan, the alluvial fan facies are developed. Various alluvial fans form a alluvial fan group by connecting or superimposing. The fan microfacies and fan apex microfacies appear in turn, and the gravels variation from coarse to fine, moving to fluvial sandstone facies. To the east, the river enter lacus sedimentary area, and the deltaic deposit is formed at the entrance of the lacus. According to the facial development situation of alluvial fan-meandering river-delta-lacus ,the depositional model of Penglai town formation in this area is constructed.

关 键 词：川西前陆盆地 蓬莱镇组 冲积扇 曲流河 三角洲 湖泊 

分 类 号：TE122.221[石油与天然气工程—油气勘探]