富锂煤层碎屑物源探讨--以平朔矿区安家岭煤矿太原组煤层为例  

Provenance of debris in lithium-rich coal seam:A case study of Taiyuan group coal seam in Anjialing Coal Mine,Pingshuo mining area

作　　者：成贤康 孙蓓蕾[1,3] 刘超 曾凡桂[1,3] 解锡超 畅向东[1,3] CHENG Xiankang;SUN Beilei;LIU Chao;ZENG Fangui;XIE XiChao;CHANG Xiangdong(Department of Earth Science and Engineering,Taiyuan University of Technology,Taiyuan 030024,China;Institute of Geology and Mineral Resources of Shanxi Province,Taiyuan 030001,China;Shanxi Key Laboratory of Coal and Coal Measure Gas Geology,Taiyuan University of Technology,Taiyuan 030024,China)

机构地区：[1]太原理工大学矿业工程学院,山西太原030024 [2]山西省地质矿产研究院,山西太原030001 [3]煤与煤系气地质山西省重点实验室,山西太原030024

出　　处：《煤炭学报》2021年第7期2346-2359,共14页Journal of China Coal Society

基　　金：国家自然科学基金资助项目(41802184,U1810202,41802193)。

摘　　要：平朔矿区安家岭煤矿太原组煤层中Li,Al等有益元素的富集主要受陆源碎屑的影响,为明确其物源区,以煤层顶、底板和夹矸样品为研究对象,利用岩石薄片、ICP-OES、ICP-MS等方法对4,8,9和11号煤层的顶底板和夹矸的岩石学和地球化学特征进行分析,进而探讨了其物源属性。岩石学结果表明,研究区砂岩样品中碎屑成分以石英和岩屑为主,杂基含量低,胶结类型主要为钙质胶结。地球化学结果显示,研究区样品主要成分为SiO_(2)和Al_(2)O_(3),其他元素的含量都比较低。微量元素Li在各个煤层顶底板和夹矸中的富集系数变化较大,其中11号煤层样品中Li富集程度最高,9号煤层样品中相对富集,8号煤层样品中表现为相对亏损,4号煤层3个样品中仅有夹矸样品富集,顶底板样品均不富集。其余微量元素表现为Th,Hf,Zr和Nb等相对富集,Co,Sc,Cr,Ni,V,Rb,Cs和Ga等元素相对亏损。根据元素质量分数比值等地球化学参数和SiO_(2)-TiO_(2),Hf-La/Th,∑REE-La/Yb,Dickinson图解及DF(A-P)MT图解,结合区域地质背景,研究区富Li和不富Li的煤层顶底板和夹矸中碎屑物质主要来源于华北北缘的内蒙古隆起。这2类煤层顶底板和夹矸的源岩类型都是以长英质火成岩为主。相较于富Li煤层顶底板和夹矸,不富Li煤层样品的源岩中有更多沉积岩的加入。The enrichment of beneficial elements such as Li and Al in the Taiyuan Formation of Anjialing coal mine,Pingshuo mining area,are mainly affected by terrigenous clastics.In order to clarify the prove-nance,thin section,ICP-OES and ICP-MS were used to analyze the petrological and geochemical charac-teristics of roof,floor and gangue of No.4,8,9 and 11 coals.The petrological results show that the clastic components in the samples are mainly quartz and rock debris,the content of miscellaneous bases is low,and the type of cementation is mainly calcareous cement.Geochemical results show that the main components of the samples are SiO_(2) and Al_(2)O_(3),and the content of other elements is relatively low.The enrichment coefficient of the trace element Li in the roof and floor and the gangue of each coal seam varies greatly.Among them,the No.11 coal seam sample has the highest concentration of Li,the No.9 coal seam sample is relatively enriched,and the No.8 coal seam sample is relatively depleted,in the 3 samples of No.4 coal seam,only the gangue sample is enriched,and the roof and floor samples are not enriched.The remaining trace elements relatively enriched are Th,Hf,Zr,and Nb,while Co,Sc,Cr,Ni,V,Rb,Cs,and Ga are relatively depleted.According to geochemical parameters,such as element ratios and SiO_(2)-TiO_(2),Hf-La/Th,∑REE-La/Yb,Dickinson diagrams and DF(A-P)MT diagrams,combined with the regional geological background,they are interpreted that the debris in the Li-rich and non-Li coal seams in the study area are mainly originated from the Inner Mongolia uplift of the northern margin,North China.The source rock types of the roof,floor and gangue samples are mainly felsic igneous rocks.Compared with the roof,floor,and gangue of the Li-rich samples,there are more sedimentary rocks debris in the source rock of the non-Li coal seam.

关 键 词：平朔矿区 安家岭煤矿 富锂煤层 地球化学特征 物源 

分 类 号：P595[天文地球—地球化学] P588.21[天文地球—地质学]