川西甘孜-理塘构造带侏罗纪海相地层的特征  

Marine Jurassic strata of Graze-Litang structural belt in western Sichuan,China

作　　者：王全伟[1] 戴宗明[1] 阚泽忠[1] 王康明[1] 梁斌[2] 

机构地区：[1]四川省地质调查院,四川成都610081 [2]西南科技大学环境与资源学院,四川绵阳621000

出　　处：《地质通报》2009年第7期907-914,共8页Geological Bulletin of China

基　　金：中国地质调查局<1:25万蒙沙村幅;石渠县幅区域地质调查>项目(编号:200313000051)资助

摘　　要：在川西高原沿甘孜-理塘构造带新发现一套侏罗纪地层,厘定为立洲组和瑞环山组。立洲组由陆源碎屑岩和基性火山岩建造组成,属山间坳陷-河湖相-滨海相沉积环境;瑞环山组为浅海碳酸盐台地沉积环境,广泛发育包括含生物礁灰岩在内的碳酸盐岩建造。立洲组含植物孢粉化石,瑞环山组含丰富的珊瑚、水螅、层孔虫、腹足、苔藓、藻类等化石,自下而上可划分为Verrucosisporites sp.-Punctatisporites sp.,Thecosmilia cf.weberi-Pyotethmos cf.discus和Cladocoropsis mirabilis-Bauneia sp.三个生物组合带。以立洲组中的孢粉和柱状节理玄武岩(Ar-Ar法)194.8Ma的年龄值为依据,将该组的时代暂定为早-中侏罗世;瑞环山组生物化石丰富,其时代属晚侏罗世。A set of Jurassic stratum along Graze - Litang structural belt in western Sichuan plateau has been discovered newly, and has been set for the Lizhou Formation and the Ruihuanshan Formation. The Lizhou Formation was formed by terrigenous clastic rocks, basic volcanic rocks, and belongs to the mountain depression - fluvio-lacustrine - littoral sedimentary environment. The Ruihuanshan Formation belongs to shallow marine carbonate rock mesa sedimentary environment with reek .The Lizhou Formation includes plant sporule, and the R.uihuanshan Formation is abundant fossils of coral, hydra, stromatoporoids, pleopod, moss and alga. From bottom to top, the latter can be divided into three biologic assemblages： Verrucosisporites sp.-Punctatisporites sp., Thecosmilia cf .weberi -Pyotethmos cf. diseus and Cladocoropsis mirabilis -Bauneia sp..According to the sportfle in the rocks of Lizhou Formation and the age of 194.8Ma of basalt （At-At method）, it is tentatively scheduled for the Early-Middle Jurassic. The R.uihuanshan Formation contains abundant biologic fossils, its era pertains to Late Jurassic.

关 键 词：川西高原 甘孜-理塘构造带 侏罗纪地层 

分 类 号：P534.52[天文地球—古生物学与地层学]