贵州瓮安岚关磷矿元素特征及沉积环境分析

为了详细研究贵州瓮安岚关地区晚震旦世灯影期元素特征及沉积环境演化,对该区广泛发育的叠层石磷块岩进行了系统采样分析。结果表明,叠层石磷块岩中较高的Ca/(Ca+Fe)值及纹层构造的发育,指示研究区沉积期属于超咸水环境;而Sr/Ba值则说明沉积期古海水盐度发生多次改变。微量元素总量、Sr含量以及1000×(Sr/Ca)值等反映沉积期瓮安岚关一带水体深度较浅,水深变化频繁。Fe的存在形式、V/Cr及Ceanom值说明沉积期岚关地区处于一个较为氧化环境中。而Al/Ti值及Mg/Ca值则说明沉积期岚关地区降雨量较多,古气候较潮湿。

Element Characteristics and Sedimentary Environment of Phosphorite from Weng'an County,Guizhou Province, China

This paper studies characteristics of elements and evolution of sedimentary environment of the phosphorites from the Late Sinian of Languan area in Weng''an County, Guizhou Province, China. Results show that higher ratios of Ca/(Ca+Fe) and the growth circumstances of laminar structures reveal that the sedimentary environment is a hypersaline water environment; on the other hand, the Sr/Ba ratios illustrate that the ancient seawater salinity experienced several times of changes. The total value of trace elements, the value of Sr and the ratios of 1000×(Sr/Ca) reflect that the water depth of the sedimentary period in Languan area is shallower and also experiences frequently changes. The existing forms of Fe, the ratios of V/Cr and the value of Ce_anom indicate that the sedimentary environment for phosphorites is oxidization. The ratios of Al/Ti and Mg/Ca show that there is more rainfall during the sedimentary period with moist climate.