火山灰蚀变粘土岩夹矸对煤中矿物异常和微量元素富集的影响机理

项目名称： 火山灰蚀变粘土岩夹矸对煤中矿物异常和微量元素富集的影响机理

项目编号： No.41302128

项目类型： 青年科学基金项目

立项/批准年度： 2014

项目学科： 天文学、地球科学

项目作者： 赵蕾

作者单位： 中国矿业大学（北京）

项目金额： 26万元

中文摘要： 煤的矿物组成和组合关系是多种地质和地球化学作用过程以及不同性质的物源物质共同影响的结果。降落到泥炭沼泽的火山灰物质经常是煤中矿物异常（种类和组合）以及微量元素富集的原因。火山灰蚀变粘土岩夹矸在我国西南地区晚二叠世含煤岩系中普遍分布。尽管自然界中绝大多数火山灰蚀变粘土岩夹矸的原始物质是酸性或中酸性，西南地区晚二叠世含煤岩系中广泛分布碱性和基性火山灰。项目拟以西南地区主要矿区晚二叠世煤和火山灰蚀变粘土岩夹矸为主要研究对象，揭示火山灰蚀变粘土岩夹矸对煤中矿物种类、组合和微量元素富集的影响。对比研究受火山灰影响和正常沉积作用形成煤层的矿物学和地球化学特征，重点探讨不同性质的火山灰对煤层中矿物异常和微量元素富集的影响，以及成煤介质条件与煤阶演化对火山灰矿物迁变的制约作用。

中文关键词： 煤；火山灰蚀变黏土岩夹矸；矿物；微量元素；稀土元素

英文摘要： The composition and association of minerals in coal are attributed to different inorganic processes and sedimentary input that were associated with coal formation. Among these factors, leaching of volcanic ashes would be expected to result in mineralogical anomalies (species and associations) and enrichment of trace elements. Tonsteins are widely developed in the Late Permian coal-bearing sequences of southwestern China. Although the geochemistry of most tonsteins in the world indicates an origin of silicic or silicic to intermediate volcanic ash fallout, alkali and mafic tonsteins that were developed in the Late Permian coal-bearing sequences of southwestern China have also been reported. This project is intended to investigate the mechanism of the formation of minerals in coal seams that contain tonsteins, by evaluating a couple of typical Late Permian coal seams in southwestern China. Comparative study will be conducted on the mineralogy of coals that were influenced by volcanic ashes and those formed under more normal depositional conditions, with an emphasis on evaluating the influence of volcanic ashes of different chemical compositions on coal mineralogy, as well as on evaluating the effect of peat-forming conditions and coal rank advance on mineralogical composition of tonsteins.

英文关键词： coal；tonsteins；minerals；trace elements；rare earth elements