东南沿海火山岩地区火山黏土型锂矿的发现

Discovery of Volcanic Clay-type Lithium Deposit in Region of Volcanic Rocks Along the Southeastern Coast of China

广东省东北部石人背盆地上白垩统叶塘组中存在锂元素超常富集现象(Li_(2)O含量可达0.2%以上),具有寻找黏土型锂矿的良好前景。石人背盆地综合剖面测量、全岩地球化学分析及岩相学观察表明,锂的富集层位位于叶塘组中—上部页岩、泥岩和粉砂岩中,黏土矿物是锂的主要载体矿物,其成因与火山活动密切相关,初步判断为火山活动相关的黏土型锂矿。盆地构造为锂矿形成提供了有利的沉积环境,富锂沉积层的厚度可观,连续富矿的层位厚度可达226 m,找矿潜力较大。该矿的发现为中国东南沿海火山岩地区寻找超大型火山岩相关沉积型锂矿提供了重要的找矿线索。

We report the lithium enrichment in the late Cretaceous Yetang Formation,located in the Shirenbei Basin,northeast of Guangdong Province.The Li_(2)O content is greater than 0.2%,and can be a target for extracting lithium.Comprehensive crosssections of the Shirenbei Basin,geochemical analyses and lithofacies interpretation suggest that the lithium-enriched layers occur in shale,mudstone and siltstone,located in Middle-Upper Yetang Formation;lithium is mainly stored in clay minerals,whose formation is closely related to volcanic activities.It was initially interpreted as a volcanic-type lithium-rich clay deposit.The basin structure provides the environment for sedimentation and concentration of lithium.The layers containing enriched lithium are approximately 226 meters thick in total,and are in great potential for extracting lithium deposit.This discovery provides fclues on investigating large-scale lithium-rich clay deposits related to volcanic activities along the southeast coast of China.