地学前缘 ›› 2024, Vol. 31 ›› Issue (4): 258-280.DOI: 10.13745/j.esf.sf.2023.11.20

• 非主题来稿选登:岩石成因与成矿关系 • 上一篇    下一篇

黔西北普底地区富锂黏土岩地球化学特征及成因

张七道1,2(), 李德宗1,2,*(), 李致伟1,2, 王东晖1,2, 于一帆1,2, 朱星强1,2, 蔡泉宇1,2, 李明1,2   

  1. 1.中国地质调查局 昆明自然资源综合调查中心, 云南 昆明 650100
    2.自然资源部 自然生态系统碳汇工程技术创新中心, 云南 昆明 650100
  • 收稿日期:2023-09-04 修回日期:2023-10-26 出版日期:2024-07-25 发布日期:2024-07-10
  • 通信作者: * 李德宗(1989—),男,工程师,主要从事矿产勘查及成矿预测工作。E-mail: ynztldz@qq.com
  • 作者简介:张七道(1986—),男,高级工程师,主要从事矿产勘查及成矿预测工作。E-mail: 506676421@qq.com
  • 基金资助:
    中国地质调查局项目(DD20220967);中国地质调查局项目(DD20220981)

Geochemical characteristics and genesis of lithium rich clay rocks in the Pudi area of northwestern Guizhou

ZHANG Qidao1,2(), LI Dezong1,2,*(), LI Zhiwei1,2, WANG Donghui1,2, YU Yifan1,2, ZHU Xingqiang1,2, CAI Quanyu1,2, LI Ming1,2   

  1. 1. Kunming General Survey of Natural Resources Center, China Geological Survey, Kunming 650100, China
    2. Technology Innovation Center for Natural Ecosystem Carbon Sink, Ministry of Natural Resources, Kunming 650100, China
  • Received:2023-09-04 Revised:2023-10-26 Online:2024-07-25 Published:2024-07-10

摘要:

黔西北普底地区二叠系梁山组直接不整合于寒武系娄山关组之上,梁山组黏土岩中有锂的超常富集现象,研究其富集机制可为黏土岩中锂资源开发与评价提供更为丰富的信息。采用激光剥蚀电感耦合等离子质谱仪(LA-ICP-MS)分析、LA-ICP-MS面扫分析、矿物自动定量分析系统(AMICS)、X衍射和扫描电镜等手段,结合U-Pb年代学研究,对黏土岩中富集的锂开展元素地球化学、物质来源及赋存状态研究。研究结果表明:富锂黏土岩产于中二叠统梁山组中下部,锂矿化体产状受下伏基底娄山关组白云岩岩溶不整合面控制。富锂黏土岩中Li,Ga,V,Nb,Zr和F等元素相对富集,Ba和Sr等元素相对贫化。富锂黏土岩富集轻稀土元素,轻稀土元素以La、Ce和Nd为主,重稀土元素以Y为主。富锂黏土岩以淡水陆相沉积为主,具有陆相、海陆过渡相和海相多相沉积特征,沉积环境以氧化环境为主,形成于热带-亚热带温湿气候。富锂黏土岩锆石年龄谱约具有2.5 Ga、1.4 Ga、980 Ma、780 Ma和530 Ma 5个峰值,其中主要峰约为980、780和530 Ma。初步认为研究区梁山组富锂黏土岩具有多重物源,寒武系娄山关组不纯白云岩可能为主要物源,黏土岩中的Li主要赋存于高岭石中。

关键词: 富集机制, 物源, 赋存状态, 沉积型锂矿, 黔西北普底地区

Abstract:

The Permian Liangshan Formation in the Pudi area of northwest Guizhou Province directly overlays the Cambrian Loushanguan Formation, exhibiting abnormal lithium enrichment in its clay rocks. Studying the enrichment mechanism provides valuable insights for lithium resource development and evaluation in clay rocks, as well as understanding lithium accumulation mechanisms. Various analytical methods including LA-ICP-MS, mapping, AMICS, XRD, SEM, along with U-Pb chronology, are employed to elucidate the elemental geochemistry, provenances, and occurrence states of lithium enrichment in clay rocks. Results reveal lithium-rich clay rocks primarily in the middle and lower sections of the Permian Liangshan Formation, with their occurrence controlled by the karst unconformity surface of the underlying Loushanguan Formation dolomite. Enriched elements such as Li, Ga, V, Nb, Zr, and F are identified, while Ba and Sr are relatively depleted. Light rare earth elements (La, Ce, Nd) predominate, with Y as the main heavy rare earth element. Lithium-rich clay rocks comprise terrestrial deposits with characteristics of terrestrial, transitional, and marine phases, formed in an oxidized environment under a tropical-subtropical warm and humid climate. The zircon age spectrum exhibits five peaks at 2.5 Ga, 1.4 Ga, 980 Ma, 780 Ma, and 530 Ma, with the main peaks at 980 Ma, 780 Ma, and 530 Ma. Lithium in the clay rocks mainly occurs within kaolinite, indicating multiple sources, with impure dolomite of the Cambrian Loushanguan Formation likely being the primary source.

Key words: enrichment mechanism, provenances, existence state, sedimentary lithium deposit, Pudi area, northwest Guizhou

中图分类号: