| 古泥炭沉积环境及其对微量元素的控制:以宁武煤田东露天煤矿11#煤层为例* |
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| 引用本文： | 王国权,孙蓓蕾,刘超,武杰,潘欣雨,$\boxed{\hbox{曾凡桂}}$.古泥炭沉积环境及其对微量元素的控制:以宁武煤田东露天煤矿11#煤层为例*[J].古地理学报,2022,24(6):1210-1223. |
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| 作者姓名： | 王国权 孙蓓蕾 刘超 武杰 潘欣雨 $\boxed{\hbox{曾凡桂}}$ |
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| 作者单位： | 1.太原理工大学矿业工程学院, 山西太原 030024;2.煤与煤系气地质山西省重点实验室, 山西太原 030024;3.煤与煤层气共采国家重点实验室, 山西晋城 048012 |
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| 基金项目： | *国家自然科学基金项目(编号:U1810202,41872177)、国家重点研发计划项目(编号:2021YFC2902002)和山西省重大科技专项(编号:20191102001)联合资助 |
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| 摘 要： | 古泥炭形成时期沉积环境对煤中微量元素的富集具有重要的影响,而煤相和相关地球化学参数是指示古泥炭沉积环境的重要标志。以宁武煤田平朔矿区东露天煤矿11#煤层为例,利用煤相参数、地球化学参数和矿物学特征对东露天11#煤层的古泥炭沉积环境进行了重建,并探讨了沉积环境对微量元素富集的影响。结果表明: (1)东露天煤矿11#煤层煤相类型包括障壁岛潟湖低位沼泽相、下三角洲平原低位沼泽相和上三角洲平原低位沼泽相3种类型,受海侵影响,沼泽水体pH、古盐度、氧化还原状态和水动力条件呈现动荡变化; (2)11#煤层中元素Li(平均133.50 μg/g)、Zr(平均198.12 μg/g)和Pb(平均60.76 μg/g)含量远高于世界硬煤; (3)微量元素在11#煤层剖面中表现为2种不同的组合,即Li-Zr-Nb-Ta-Hf组合和Pb-Cu-Ga-Ge-Tl-REY组合,前者主要在DLT-11-2、DLT-11-6和DLT-11-10这3个层位富集,这些层位具有相似的沉积环境,为海水(咸水)、酸性、缺氧—还原、水动力较强、硫含量相对较低的障壁岛—潟湖低位沼泽相,而后者主要在DLT-11-0、DLT-11-4和DLT-11-8这3个层位富集,沉积环境也相似,为海水(咸水)、碱性、氧化或缺氧、水动力较弱、硫含量相对较高的下三角洲平原低位沼泽相。该成果将为含煤盆地关键金属矿产资源的勘探开发和煤炭资源的清洁利用提供理论依据。
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| 关 键 词： | 煤层 微量元素 沉积环境 地球化学 宁武煤田 山西 |
| 收稿时间： | 2022-01-24 |
Paleo-peat sedimentary environment and controlling on trace elements: example from the 11# coal seam in Donglutian Coalmine of Ningwu Coalfield |
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| WANG Guoquan,SUN Beilei,LIU Chao,WU Jie,PAN Xinyu,$\boxed{\hbox{ZENG Fangui}}$.Paleo-peat sedimentary environment and controlling on trace elements: example from the 11# coal seam in Donglutian Coalmine of Ningwu Coalfield[J].Journal of Palaeogeography,2022,24(6):1210-1223. |
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| Authors: | WANG Guoquan SUN Beilei LIU Chao WU Jie PAN Xinyu $\boxed{\hbox{ZENG Fangui}}$ |
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| Institution: | 1.College of Mining Engineering,Taiyuan University of Technology,Taiyuan 030024,China;2.Shanxi Key Laboratory of Coal and Coal-measure Gas Geology,Taiyuan 030024,China;3.State Key Laboratory of Coal and CBM Co-Mining,Shanxi Jincheng 048012,China |
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| Abstract: | The paleopeat-forming environments plays an important role in the enrichment of trace elements in coal. Coal facies and related geochemical parameters are important indicators for the paleopeat environmental condition. In this paper,the coal facies parameters,geochemical parameters and mineralogical characteristics were used to reconstruct the paleopeat-forming environments of the 11# coal seam in Donglutian Coalmine from Pingshuo district,Ningwu Coalfield, and the influence of paleopeat-forming environments on trace element enrichment was discussed. The results show that: 1)The coal facies of the Donglutian Coalmine 11# coal seam include three types,i.e.,the low swamp of the barrier island lagoon,lower delta plain and upper delta plain. Under the influence of transgression,the pH,paleosalinity,redox degree and hydrodynamic conditions of marsh water show the periodic variation. 2)The contents of Li with an average value of 133.50μg/g,Zr with an average value of 198.12μg/g and Pb with an average value of 60.76μg/g in 11# coal seam are much higher than those of the hard coal in the world. 3)In the profile of coal seam,trace elements in 11# coal seam show two different assemblages, i.e.,Li-Zr-Nb-Ta-Hf and Pb-Cu-Ga-Ge-Tl-REY. The former assembly is mainly enriched in DLT-11-2,DLT-11-6 and DLT-11-10,which are characterized by similar sedimentary environments,i.e.,seawater,anoxic to euxinic conditions,strong hydrodynamic conditions,with relatively low sulfur content,the low swamp facies in the barrier island-lagoon. The latter assembly is mainly enriched in DLT-11-0、DLT-11-4 and DLT-11-8,which are characterized by similar sedimentary environments,i.e.,seawater,alkaline,oxic or anoxic conditions,weak hydrodynamic conditions,with relatively high sulfur content,lower swamp facies of the lower delta plain. These results would provide valuable theoretical basis for reasonable mining target selection of metal mineral resources and clean utilization of coal resources in other coal-bearing basins. |
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| Keywords: | coal seam trace elements sedimentary environment geochemistry Ningwu Coalfield Shanxi Province |
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