扬子板块北缘镇巴地区下二叠统梁山组富锂黏土岩地质特征及成因初探  

Geological characteristic and genesis of lithium-enriched claystone in Lower Permian Liangshan Formation,Zhenba area,northern margin of Yangtze Plate

作　　者：祁晓鹏 周伟 徐磊 张嘉升 杨杰 QI Xiaopeng;ZHOU Wei;XU Lei;ZHANG Jiasheng;YANG Jie(Sino Shaanxi Nuclear Industry Group Geological Survey Co.,Ltd.,Xi’an 710100,Shaanxi,China)

机构地区：[1]中陕核工业集团地质调查院有限公司,陕西西安710100

出　　处：《矿产勘查》2025年第1期129-141,共13页Mineral Exploration

基　　金：陕西省地质勘查基金项目(61201908341);中陕核工业集团公司科技攻关项目(61210103)联合资助。

摘　　要：本文报道了扬子板块北缘镇巴地区下二叠统梁山组黏土岩系锂的超常富集特征,黏土岩Li2O最高含量0.85%,具有潜在的开发利用价值。为了查明该套富锂黏土岩的地质特征及锂的赋存状态,本文通过详细的野外地质调查、X射线衍射(XRD)、扫描电镜-能谱(SEM-EDS)、岩石地球化学分析等手段,查明了梁山组黏土岩的沉积层序和富锂黏土岩的黏土矿物组成,分析了沉积母岩及沉积物质来源,讨论了锂的赋存状态。研究表明,镇巴地区下二叠统梁山组黏土岩产于梁山组(P1l)/罗惹坪组(S1l)平行不整合界面,为一套铁-铝质黏土岩、炭质黏土岩组合,表现为底部富铁、中部富铝、顶部富炭质的总体特征,富锂黏土岩产于该套黏土岩的上部层位。梁山组富锂黏土岩主要由石英、伊利石、绿泥石组成,含少量钾长石、锐钛矿等矿物。主量元素(SiO_(2)、Al_(2)O_(3)、TFe_(2)O_(3)、Ti O_(2))特征表明黏土岩属于铝质黏土岩。岩石地球化学特征表明梁山组黏土岩来源于中—基性岩浆岩,结合区域地质资料及对比分析,认为梁山组黏土岩沉积物源主要为扬子板块基底——汉南杂岩,富锂黏土岩锂主要赋存于锂绿泥石中。研究成果可为富锂黏土岩的研究提供科学参考,亦可指导本地区扬子板块北缘黏土岩型锂矿的勘查工作。This paper reports the supernormal enrichment characteristics of lithium in the claystone series of the Lower Permian Liangshan Formation in Zhenba area,northern margin of the Yangtze Plate.The highest content of Li2O in the claystone is 0.85%,which has potential development significance.In order to find out the geological characteristics of this set of lithium-rich claystone and the occurrence state of lithium,This paper identifies the sedimentary sequence of Liangshan Formation claystone and the clay minerals composition of lithium-enriched claystone,investigates the source of sedimentary parent rock and sedimentary material,demonstrates the occurrence state of lithium,throughdetailed field geological survey,X-ray diffraction(XRD)analysis,scanning electron microscopy-energy dispersive spectrometry(SEM-EDS)and geochemical analysis.The study shows that the Liang⁃shan claystone in Zhenba area develops in the parallel unconformity interface of Liangshan Formation(P1l)/Luo⁃reping Formation(S1l),which is a set of iron-aluminum claystone and carbonaceous claystone combination.Lithium-enriched claystone is produced in the upper layer of this set of claystone series.The Liangshan Formation lithium-enriched claystone is mainly composed of quartz,illite and chlorite,with a small amount of feldspar and anatase.The characteristics of major elements(SiO_(2)、Al_(2)O_(3)、T Fe_(2)O_(3)、TiO_(2))show that the claystone belongs to alumi⁃num claystone.The geochemical characteristics of rocks indicate that the claystone of the Liangshan Formation are derived from intermediate-basic magmatic rocks.Combined with regional geological data and comparative analysis,this paper considers that the sediment source of the Liangshan Formation claystone is mainly the basement of the Yangtze Plate-Hannan Massif.It indicates that lithium mainly occurs in cookeite.This research results can provide scientific reference for the study of lithium-enriched claystone,and can also guide the exploration of clay-type lithium deposits in the nort

关 键 词：赋存状态 沉积物源 富锂黏土岩 梁山组 扬子板块北缘 

分 类 号：P595[天文地球—地球化学] P611[天文地球—地质学]