能量色散XRF技术在湖相沉积中的应用——以鄂尔多斯盆地中部地区为例

Application of Energy Dispersive XRF Technology in Lacustrine Sediments:A Case Study in Central Ordos Basin

能量色散X射线荧光技术在针对海相沉积地层的研究中取得了长足进步,但在湖相沉积物的运用中却较少。为了探索该技术在湖相沉积物中的适用性,特针对鄂尔多斯盆地开展了探索性研究。本研究采用配备有铑X射线的X射线荧光仪,基于不同的能量条件分别对主要元素和微量元素进行了系统的测量与分析,共计获得了29种元素的含量变化。研究结果表明,对于湖相碎屑岩沉积,基于能量色散X射线荧光的元素化学能有效区分岩性;判断物质的来源、动植物繁盛程度等古沉积环境。但是,对古生产力恢复、高精度氧化还原条件等古沉积环境的识别上还存在可靠性不高的问题。湖相沉积物元素化学的研究,需要以地质演变过程简单的盆地和地区为出发点,探索合理的地质解释模式。此外,还需要提高仪器的测量精度,重点是消除不同元素在谱图上的相互干扰。

Energy dispersive X Ray Fuorescence Technology has made great progress in studying marine sediments.However,it is rarely applied to lacustrine deposits.In order to explore the applicability of this technology,detailed geochemical analysis of the lacustrine sediments in Ordos Basin has been carried out.In this study,the major elements and trace elements were measured and analyzed using X-ray fluorescence spectrometer equipped with rhodium X-ray.Based on different energy conditions,a total of 29 elements were obtained.The results showed that,the elemental chemistry can effectively distinguish the lithology and strata,and reasonably estimate the paleo-redox environment such as source input,organism flourishing degree.However,recognition of Paleo-sedimentary environments such as paleoproductivity restoration and high-precision redox conditions is not reliable.The study of elemental chemistry in lacustrine sediments needs to starts from simple sedimental basins or tectonical regions and then complex sedimental basins,and explores the reasonable geological interpretation models.In addition,it is necessary to improve the measurement accuracy of the instrument,with the emphasis on eliminating the spectrogram interference of different elements.