摘要
沉积环境的古氧相特征是沉积环境和古海洋特征恢复的重要内容。岩石地球化学特征是判断其形成环境氧化还原条件的重要手段之一。本文以来宾地区铁桥剖面为重点,通过对栖霞组灰岩的地球化学分析,结合沉积学、古生态学特征,认为栖霞组沉积于贫氧的沉积背景,是在海水深度和海域的局限程度等沉积条件发生周期性变化的情况下形成的。古氧相地球化学指标V/(V+Ni)、Ce/La、U/Th值都适用于该组以钙质沉积为主的沉积物。黄铁矿矿化程度(DOP值)变化较大,反映该区多变的古氧相特征。
Palaeo-oxygenation facies feature is an important content for recovery of sedimentary environments and palaeoocean. Geochemistry of sediments and/or rocks in anoxic environments is commonly an important indicator for the interpretation of palaeoredox conditions. Analyses of limestone samples collected from the Qixia Formation, integrated with their sedimentary and palaeoecological characteristics, have confirmed that the carbonate successions in the study area were accumulated in a dysaerobic environment. It is suggested that most geochemical indices, for example, U/Th, V/(V+Ni) and Ce/La are valid for the interpretation of argillaceous limestones. The DOP data vary widely, indicating a changeable feature of the palaeo-oxygenation facies.
出处
《矿物岩石地球化学通报》
CAS
CSCD
2004年第2期144-148,共5页
Bulletin of Mineralogy, Petrology and Geochemistry
基金
国家自然科学基金资助项目(49002030)
国家重点基础研究发展规划项目(G1999043200)
