广西扶绥东攀剖面二叠纪—三叠纪之交古生产力演化  

Paleoproductivity evolution across the Permian-Triassic boundary of Dongpan section at Fusui in Guangxi

作　　者：沈俊[1] 冯庆来[2] 

机构地区：[1]中国地质大学(武汉)生物地质与环境地质教育部重点实验室,湖北武汉430074 [2]中国地质大学(武汉)地质过程与矿产资源国家重点实验室,湖北武汉430074

出　　处：《古地理学报》2010年第3期291-300,共10页Journal of Palaeogeography：Chinese Edition

基　　金：国家自然科学基金项目(批准号:40839903);中国石油化工股份有限公司海相油气勘探前瞻性项目(编号:G0800-06-ZS-319);教育部高等学校博士学科点专项科研基金项目(编号:20060491502)联合资助

摘　　要：用不同地球化学替代指标(Al,Ba,Cu,Zn)对广西扶绥东攀剖面二叠纪—三叠纪之交古生产力进行估算表明:广西扶绥东攀剖面二叠纪—三叠纪之交的古生产力(0.31gC/m2d)与美国二叠纪含磷组黑色页岩的古生产力(1.40gC/m2d)、华南巢湖大隆组古生产力(1.48gC/m2d)相比总体偏低,且自下而上逐渐增大,可以分为4个演化阶段:波动期、衰退期、繁盛期和爆发期。生产力的演化与火山物质的注入有很好的相关性,火山作用可以促使初级生产力的繁盛。通过不同指标对比发现:生物成因Al受岩性影响比较大,陆源物质含量超过63%时不能用来指示古生产力的变化;Ba用作古生产力指标时受岩性影响不大,但在还原条件下易于流失而导致生物成因Ba(Baxs)值失真。Cu和Zn是相对稳定的古生产力估算替代指标。According to geochemistry proxies（Al, Ba, Cu, Zn）, the paleoproductivity across the Permian-Triassic boundary of Dongpan section at Fusui in Guangxi was estimated to be 0.31 gC/m2d, which is lower than that of the Permian Black Shale of the Phosphoria Formation in USA（1.40 gC/m2d）and that of the Dalong Formation of Chaohu in South China（1.48 gC/m2d）. It gradually increases upward and can be divided into four stages： The fluctuation, the decline, the flourish and the eruption stages. The productivity is closely related with volcanism. Volcanism can lead to the flourish of ordinary productivity. By comparison among different geochemistry proxies, it is indicated that Al can not be used as a productivity proxy when terrigenous materials make up over 63% of the total sediments for the reason that Al is greatly influenced by lithology. Baxs is less affected by lithology, but it easily runs off in reductive conditions. Cu and Zn are relatively stable geochemistry proxies for paleoproductivity.

关 键 词：地球化学方法 广西扶绥 东攀剖面 古生产力指标 二叠纪—三叠纪界线 

分 类 号：P593[天文地球—地球化学]