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

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 SiO2 and Al2O3,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 SiO2-TiO2,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.