淮南煤田山西组泥页岩微量元素地球化学特征及其意义

泥页岩中微量元素特征对反演泥页岩形成时的沉积和古地理气候条件具有重要意义。采集淮南煤田山西组泥页岩样品，利用ICP-MS对泥页岩中微量元素进行了测试分析，探讨了研究区山西组泥页岩中微量元素的地球化学特征及其意义。结果表明，B、Cr、U、Ga、Li、Sn、Pb、Mo、Th、W等元素富集，Cd、Co、Cu、Ti、Zn、Sc、Ba、Mn、Ni、Sr等元素亏损；揭示淮南煤田山西组形成于温暖湿润和半咸水-高咸水的沉积环境中，沉积体系为开放型，体系内为弱氧化-还原环境，其中以弱还原-还原环境为主，且表现出从早期弱氧化到中后期的还原环境的演化特征；依据U/Th、Ni/Co、Sr/Cu、B/Ga、Sr/Ba、TOC等地球化学参数结果推测，盐度和氧化还原条件受到多种因素的影响，有机质的原始堆积量是影响山西组泥页岩中有机质含量的主要因素，而盐度和氧化还原条件影响有机质中各显微组分含量。研究区温暖湿润的气候和较为还原的环境为有机质的堆积和保存提供了有利条件，为页岩气的成藏提供了物质基础。 

Geochemistry characteristics of trace elements of mud shale of Shanxi Formation in Huainan coalfield and its significance

The characteristics of trace elements in mud shale have significant importance for invesion of paleao-geog-raphic and paleo-chimate during formation of mud shale. The geochemical characteristics and its significance of trace elements of Shanxi Formation mud shale in Huainan coalfield were discussed by collection of mud shale samples and testing the content of the trace elements in shale with ICP-MS. The results show that elements B, Cr, U, Ga, Li, Sn, Pb, Mo, Th, W are enriched, and Cd, Co, Cu, Ti, Zn, Sc, Ba, Mn, Ni, Sr are of deficit; The results revealed that Shanxi Formation in Huainan coalfield was formed in a warm and humid and brackish-high saltwater sedimentary environment. The deposition system was open, the depositional environment was of weak oxidation-reduction. It was mainly the weak reduction-reducing environment, showing the characteristics of the evolution from the early weak oxidative environment to the later reductive environment. Correlation analysis of the results of U/Th, Ni/Co, Sr/Cu, B/Ga, Sr/Ba, TOC and other geochemical parameters indicate that salinity and redox conditions may be affected by many factors, the original amount of organic matter accumulation was the main affecting factor on the content of organic matter in the mud shale from Shanxi Formation, salinity and redox conditions affected the evolution of organic matter toward different macerals. Warm moist climate and reducing environmental provided favorable conditions for organic matter accumulation and preservation, provided the mate-rial basis for the shale gas reservoir.