四川盆地北部地区寒武系沧浪铺组沉积演化  

Sedimentary evolution of the Cambrian Canglangpu Formation in northern Sichuan Basin

作　　者：王振宇[1,2,3] 曾浩 屈海洲[1,2,3] 赵容容[4] 张宇[4] 李文皓 唐松[5] 张云峰[1,2,3] WANG Zhenyu;ZENG Hao;QU Haizhou;ZHAO Rongrong;ZHANG Yu;LI Wenhao;TANG Song;ZHANG Yunfeng(State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation,Southwest Petroleum University,Chengdu 610500,China;Natural Gas Geology Key Laboratory of Sichuan Province,Chengdu 610500,China;School of Geoscience and Technology,Southwest Petroleum University,Chengdu 610500,China;Exploration Division,Southwest Oil&Gas field Company,PetroChina,Chengdu 610051,China;Central Sichuan Division,Southwest Oil&Gas Field Company,PetroChina,Suining 629000,China)

机构地区：[1]西南石油大学油气藏地质及开发工程国家重点实验室,四川成都610500 [2]西南石油大学天然气地质四川省重点实验室,四川成都610500 [3]西南石油大学地球科学与技术学院,四川成都610500 [4]中国石油西南油气田分公司勘探事业部,四川成都610051 [5]中国石油西南油气田分公司川中油气矿,四川遂宁629000

出　　处：《断块油气田》2023年第5期808-815,共8页Fault-Block Oil & Gas Field

基　　金：国家自然科学基金项目“塔中地区上奥陶统良里塔格组微生物碳酸盐岩沉积特征对多尺度孔隙耦合的影响”(41702163);“米仓山地区埃迪卡拉系灯影组核形石微组构及环境意义”(41702122)。

摘　　要：四川盆地下古生界寒武系沧浪铺组勘探潜力巨大。文中结合钻井和野外地质剖面实测成果等最新资料,研究了四川盆地北部地区沧浪铺组沉积演化规律。结果表明:1)沧浪铺组沉积期,研究区内可识别出开阔台地相、局限台地相和潮坪相3种沉积相类型,纵向上具有明显的分异特征,横向上沉积厚度西薄东厚。沧一段沉积期,开阔台地相发育以鲕粒石灰岩、砂屑石灰岩为主要岩性并可见小型槽状交错层理的台内滩亚相,和以泥晶石灰岩为主要岩性的滩间海亚相;局限台地相发育以具有残余结构的砂屑白云岩和鲕粒白云岩为岩性并可见重结晶作用的台内滩亚相,和以灰质泥晶白云岩、砂质白云岩为主要岩性的滩间海亚相;在裂陷槽和古隆起之间区域,发育以泥质白云岩、泥灰岩和砂质白云岩为主要岩性的混积潮坪相。沧二段沉积期,发育以紫红色泥岩、砂岩等为主要岩性的碎屑潮坪相,见小型水平层理、羽状交错层理和砂岩透镜体。2)沧浪铺组沉积期,以大规模海退为主,水体总体逐渐变浅。沧一段沉积期,碎屑物质输入受到裂陷槽隔档作用影响,发育碳酸盐岩沉积,在构造高部位发育以颗粒岩为主的台内滩亚相。至沧一段沉积末期,裂陷槽逐渐被填平,碎屑物质得以向东持续迁移。沧二段沉积期,发生了小规模的海侵—海退过程,水体由深变浅,最终形成以砂泥岩互层沉积为主要特征的碎屑潮坪沉积环境。The Lower Paleozoic Cambrian Canglangpu Formation in Sichuan Basin has great exploration potential.The sedimentary evolution law of Canglangpu Formation in northern Sichuan Basin was studied based on the latest data of drilling and field geological section measurement.The results show that:(1)during the sedimentary period of the Canglangpu Formation,three types of sedimentary facies can be identified in the study area,including open platform facies,restricted platform facies and tidal flat facies.There are obvious features of vertical differentiation,and the horizontal sedimentary thickness is thin in the west and thick in the east.During the sedimentary period of the first Member of Canglangpu Formation,the intra-platform beach subfacies with oolitic limestone and sand-debris limestone as the main lithology and visible small trough cross-bedding,and the beach interact sea subfacies with micritic limestone as the main lithology were developed within the open platform facies.And the intra-platform shoal subfacies with sand-debris dolomite and oolitic dolomite with relict texture as lithology and visible recry-stallization,and the beach interact sea subfacies with calcareous micrite dolomite and sandy dolomite as the main lithology were developed within the restricted platform facies.The mixed tidal flat facies with argillaceous dolomite,marl and sandy dolomite as the main lithology are developed in the area between the taphrogenic trough and the paleo-uplift.The clastic tidal flat facies with purplish-red mudstone and sandstone as the main lithology were developed during the sedimentary period of the second Member of Canglangpu Formation,and small horizontal bedding,pinnate cross bedding and sandstone lens can be seen.(2)During the deposition period of the Canglangpu Formation,it was dominated by large-scale regression,and the water body gradually became shallow on the whole.During the sedimentary period of the first Member of Canglangpu Formation,the import of clastic materials was affected by the barrier effect

关 键 词：沉积相 沉积演化 沧浪铺组 北斜坡 四川盆地 

分 类 号：TE121.3[石油与天然气工程—油气勘探]