摘要
西藏改则上三叠统日干配错组发育了一套厚度较大的碳酸盐岩台地相沉积。利用研究区内39件碳酸盐岩样品的常量元素和微量元素相关关系、组分含量及特征元素的比值特征,来探讨元素地球化学特征与沉积环境的关系。研究表明,1Mn/Sr值均小于1,平均值为0.28,表明碳酸盐岩基本没有受到成岩作用的影响;2Al2O3、K2O和Fe2O3呈正相关关系,它们与Ga O呈负相关关系,与Ni、V呈正相关关系;Fe2O3与Mn、Ba、Ni呈正相关关系;3Sr、V、Ba、Mn含量从浅水到深水环境总体呈增加趋势;4根据Sr、K、Na、Ca含量、Sr/Ba、V/(V+Ni)值特征分析了日干配错组沉积期的古气候和古环境。结果显示,日干配错组总体上为温暖潮湿气候下的陆表海还原沉积环境,显现出海侵的趋势。
The Riganpeicuo Formation in Garze,Tibet,is a series of carbonate platform facies strata. By the geochemical analysis of 39 carbonate samples,this paper discusses the sedimentary geochemistry characteristics and the palaeosedimentary environment significance of the Riganpeicuo Formation. The results indicate that： （1）Mn/Sr ratio of all tested samples is less than 1,with the mean value of 0. 28,which shows that the Riganpeicuo Formation carbonate rocks were little affected by the diagenesis. （2）Al2O3,K2 O and Fe2O3 are positively correlated,they negatively correlate with Ga O,and positively correlate with Ni,V; Fe2O3 correlates positively with Mn,Ba,and Ni.（ 3）the contents of Sr,V,Ba,Mn,show an deepening trend from shallow to deep water environment.（ 4）according to the contents of Sr,K,Na,Ca and the ratio characteristics of Sr/Ba,V /（ V＋Ni） etc.,this paper analyzes the paleoclimate and palaeoenvironment of development period of the Riganpeicuo Formation. In brief,the Riganpeicuo Formation is epicontinental deposits developed in warm humid climate and reducing environment,with a transgressive process.
出处
《矿物岩石地球化学通报》
CAS
CSCD
北大核心
2015年第3期556-563,共8页
Bulletin of Mineralogy, Petrology and Geochemistry
基金
中国地质调查局地质调查项目(2-5-2011-67)
中央高校基本科研业务费项目(2011YYL118)
关键词
地球化学
古环境
上三叠统日干配错组
西藏改则
geochemistry
paleoenvionment
the Upper Triassic Riganpeicuo Formation
Gaize Tibet
