云南中基性火山岩风化壳离子吸附稀土成矿作用分析——以腾冲龙井山安山岩风化壳型稀土矿床为例  

Mineralization of Ion-adsorption Type Rare Earth in Intermediate-basic Volcanic Rocks: A Case Study of Rare Earth Deposits from Longjingshan, Tengchong, Yunnan Province

作　　者：曾招金 祝向平 张彬[3] 高儒东[1] ZENG Zhao-jin;ZHU Xiang-ping;ZHANG Bin;GAO Ru-dong(Kunming Geological Exploration Institute of China Metallurgical Geology Bureau,Kunming,Yunnan 650203;Chengdu University of Technology,Chengdu,Sichuan 610059;Chengdu Center,China Geological Survey,Chengdu,Sichuan 610081)

机构地区：[1]中国冶金地质总局昆明地质勘查院,云南昆明650203 [2]成都理工大学,四川成都610059 [3]中国地质调查局成都地质调查中心,四川成都610081

出　　处：《地球学报》2021年第6期936-944,共9页Acta Geoscientica Sinica

基　　金：中国地质调查局地质调查项目“滇西地区三稀等重要矿产地质调查”(编号:DD20179604)资助。

摘　　要：近年来在云南发现了多个离子吸附型稀土矿,特别是滇西的腾冲-陇川地区、临沧-勐海地区成为了找矿突破最大、最受关注的地区。本次工作在腾冲火山岩带南部龙井山发现一套富含轻稀土的第四系中基性火山岩建造,该含矿建造稀土元素丰度平均值达532×10^(-6)。经过系统的调查研究及采样工作,结果表明腾冲龙井山新近纪中的辉石安山岩富含轻稀土,为一种年轻火山岩形成的风化壳型稀土矿床,矿体平均厚度9.15 m,平均品位(TREEO)0.11%,矿体品位、厚度变化与风化壳厚度呈正相关。该中基性火山岩离子吸附型稀土矿床的发现丰富了云南稀土矿床类型。这种年轻的中基性火山岩型稀土矿的成矿地质背景、地球化学特征等,为寻找中基性岩有关的稀土矿床提供参考。In recent years, many ion-adsorbed-type rare earth(IATRE) ore deposits have been found in Yunnan.Tengchong–Longchuan and Lincang–Menghai have become the most studied and prospected areas for IATRE ore deposits. In this study, a Quaternary intermediate-basic volcanic formation was found in the Longjinghsan area within the southern Tengchong Volcanic Rock Belt. The average abundance of rare earth elements in the formation is 532×10^(-6). Systematic investigation and sampling of the volcanic formation have shown that the pyroxene andesites in Longjingshan, Tengchong, belong to an IATRE ore deposit rich in light rare earth elements,which formed from young volcanic rocks. The orebody has an average thickness of 9.15 m, and an average grade(total rare earth element oxides, TREEO) of 0.11%, which varies from the average grade. The thickness of the orebodies is positively correlated with the thickness of the weathering shelf of the volcanic rocks. The discovery of an IATRE ore deposit in the Tengchong area adds to the types of rare earth ore deposits in Yunnan.The geological setting and geochemical characteristics of the young intermediate-basic volcanic rare earth ore deposit illustrates that rare earth deposits are related to intermediate-basic volcanic rock.

关 键 词：中基性火山岩 离子吸附型稀土矿 成矿作用 腾冲龙井山 云南 

分 类 号：P594.2[天文地球—地球化学] P611[天文地球—地质学]