摘要
通过大量岩心、薄片、测井、地震等资料的综合分析,研究了川西北地区上二叠统吴家坪组沉积相类型、分布特征及平面分布演化。川西北地区吴家坪组发育泥页岩、碳酸盐岩及火山碎屑岩等岩性,沉积相可划分为滨岸平原及沼泽、缓坡、开阔台地、台地边缘、斜坡和陆棚共6种。吴一段沉积初期,海水侵覆于下伏茅口组岩溶古地貌之上,研究区沉积水体较停滞,为较还原环境的滨岸平原与沼泽相,形成了吴一段底部的页岩等细粒沉积岩;吴一段沉积中晚期相对海平面上升,研究区内开始大范围发育缓坡沉积,St10井-Yb7井一带的西南部是以滩体沉积为主的浅缓坡亚相,西北部则是低能滩间洼地夹低能滩的深缓坡亚相;吴二段沉积期,受局部同沉积断层等影响,深缓坡沉积范围向西南方向扩大;持续的大规模滩体建造和构造沉降,使得吴三段沉积时期,在St9井-Lg70井-Yb7井一带出现亮晶颗粒灰岩夹微生物黏结岩等形成了弱镶边台地边缘沉积特征,其西南部为开阔台地相等浅水沉积,东北部为斜坡、陆棚等较深水沉积。因此,川西北地区的吴家坪组经历了滨岸平原及沼泽相、缓坡相、弱镶边台地相/斜坡相/陆棚相共3种沉积体系的演化。
The sedimentary facies types,distribution characteristics and plane distribution of the Upper Permian Wujiaping Formation in the northwestern Sichuan are studied by comprehensive analysis of a large number of core,section,logging,and seismic data. In the Wujiaping Formation of northwestern Sichuan Basin,there are mudstone,carbonate and pyroclastic rocks. The sedimentary facies can be divided into six species,such as the shore plain and the marsh,the ramp,the open-platform,the platform margin,the slope and the continental shelf. In the early stage of Wu 1 member,the seawater intruded on the karst ancient landform of the underlying Maokou Formation. Since the sedimentary water in the study area was relatively stagnant,the reductive environment was the shore plain and the swamp facies which formed fine-grained sedimentary rock,such as the shale at the bottom of the Wu 1 member. The relative sea level rose in the middle and late Wu 1 member,and the ramp deposition began on large scale in the study area. The southwestern part of St10-Yb7 area was the shallow ramp subphase dominated by all kinds of shoal deposits,and the north part was the deep ramp subphase which was the low energy interbank depression with low energy shoals. In the sedimentary period of Wu 2 member,the study area was affected by the local co-deposition fault and the like,the deposition range of the deep ramp was expanded to the southwest. The continuous large-scale shoals construction and the construction settlement analysis are carried out,so that during the time of the Wu 3 member,there is a thick,bright-grained limestone with microorganism-bonded rock and so on,forming the sedimentary features of the weak-rimmed platform in the St9-Lg70-Yb7 area. The southwestern part was deposited in open platform facies. The slope,and the continental shelf are deposited in northeastern part. Therefore,the Wujiaping Formation in the northwest of Sichuan has experienced the evolution of three depositional systems,such as the shore plain and the swamp,the ramp,the
作者
张本健
王宇峰
裴森奇
屈海洲
刘茂瑶
李彦锋
李泯星
张祎蕾
Zhang Ben-jian;Wang Yu-feng;Pei Sen-qi;Qu Hai-zhou;Liu Mao-yao;Li Yan-Feng;Li Min-xing;Zhang Yi-lei(Branch of Chuanxibei Gas Field,PetroChina Southwest Oil and Gas Field Company,Jiangyou 621700,China;School of Geoscience and Technology,Southwest Petroleum University,Chengdu 610500,China;Branch of Deposition and Accumulation,PetroChina Key Laboratory of Carbonate Reservoir,Chengdu 610500,China)
出处
《天然气地球科学》
EI
CAS
CSCD
北大核心
2019年第12期1709-1720,共12页
Natural Gas Geoscience
基金
国家自然科学基金（编号：41702163
41702122）
中国石油碳酸盐岩储层重点实验室开放基金（编号：2018-497）联合资助
关键词
沉积演化
缓坡
弱镶边台地
吴家坪组
上二叠统
川西北地区
Sedimentary evolution
Ramp
Weak-rimmed platform
Wujiaping Formation
Upper Permian
Northwestern Sichuan
