宜宾刘家镇上三叠统须家河组植物化石特征与古环境意义  

Plant Fossils Characteristics and Palaeoenvironment Significances ofthe Upper Triassic Xujiahe Formation in Liujia Town of Yibin City

作　　者：孙勇[1,2,3] 李振江 宋伟[1,2,3] 余旭辉 李瑞 谭耕莉[1,2] Sun Yong;Li Zhenjiang;Song Wei;Yu Xuhui;Li Rui;Tan Gengli(Sichuan Geology and Mineral Bureau Regional Geological Survey Team,Chengdu,Sichun 610213;Sichuan Rongda Mining Group Co.,LTD,Chengdu,Sichun 610213;Chongqing Key Laboratory of Paleontology and Paleoenvironment of Sichuan and Chongqing Co-Construction,Chengdu,Sichun 610213)

机构地区：[1]四川省地质矿产勘查开发局区域地质调查队,四川成都610213 [2]四川省容大矿业集团有限公司,四川成都610213 [3]川渝共建古生物与古环境协同演化重庆市重点实验室,四川成都610213

出　　处：《资源环境与工程》2023年第1期1-8,共8页Resources Environment & Engineering

基　　金：四川省自然资源厅科技项目(Kj-2022-26)。

摘　　要：对宜宾市刘家镇龙滩村一带出露的须家河组进行剖面实测和植物化石采样分析,根据岩性组合和植物化石特征,结合区域地层对比,认为仅出露须家河组三段和四段。沉积相分析表明,须家河组三段的沉积环境为湖泊相滨湖亚相滨湖沼泽和滨湖砂坝微相,须家河组四段的沉积环境为辫状河三角洲相三角洲前缘亚相水下分流河道和分流间湾微相。研究区产丰富的植物化石,主要为真蕨植物、尼尔桑及新芦木等,时代均为晚三叠世。综合分析认为,在晚三叠世时期,该区古气候特征为湿热的热带—亚热带气候。The section measurement and plant fossil sampling analysis of the Xujiahe Formation exposed in Longtan Village,Liujia Town,Yibin City are carried out.According to the lithology combination and plant fossil characteristics,combined with regional stratigraphic correlation,it is considered that only the third and fourth rock members of the Xujiahe Formation are exposed in study area.Analysis of sedimentary facies shows that the sedimentary environment of the third member of Xujiahe Formation is lacustrine facies-lakeshore subfacies-lakeshore swamp and lakeshore sandbar microfacies;the sedimentary environment of the fourth member of Xujiahe Formation is braided river delta facies-delta front subfacies-underwater distributary channel and underwater distributary interchannel bay microfacies.There are abundant plant fossils in study area,mainly are Cladophlebis,Nilssonia and Neocalamites,the sedimentary period all of which were in the late Triassic.Based on the comprehensive analysis,it reflects that in the late Triassic period,the paleoclimate of the area were humid tropical-subtropical climate.

关 键 词：植物化石 沉积环境 古气候 须家河组 上三叠统 四川盆地 

分 类 号：P512.2[天文地球—地质学] Q914.2[天文地球—古生物学与地层学]