滇西南西盟—澜沧地区土壤稀土地球化学异常的发现及找矿意义
REE geochemical anomalies in soils of the Ximeng-Lancang area in southwestern Yunnan and their discovery and their implications for ore prospecting
谢岿锐 1宋旭锋 1周坤 2周余国 3佘中明 4唐鉴1
作者信息
- 1. 云南省地质调查院,云南 昆明 650214;自然资源部 三江成矿作用及资源勘查利用重点实验室,云南 昆明 650061
- 2. 云南省地质调查院,云南 昆明 650214;云南省核工业地质调查院,云南 昆明 650106
- 3. 自然资源部 三江成矿作用及资源勘查利用重点实验室,云南 昆明 650061;云南大学 地球科学学院,云南 昆明 650091
- 4. 云南省地质勘查基金管理中心,云南 昆明 650224
- 折叠
摘要
滇西南西盟—澜沧地区属西南"三江"造山带南段,通过 1∶5 万土壤地球化学测量工作,发现研究区稀土地球化学异常 24 个,并主要集中分布在昌宁—孟连深大断裂带上及其附近的石炭系平掌组基性火山岩、石炭—二叠系鱼塘寨组碳酸盐沉积岩地层中.通过对评序靠前的AP00 稀土地球化学异常进一步进行 1∶1 万土壤地球化学测量、1∶1 万专项地质测量和少量的轻型山地探矿工程等工作的详细解剖,首次在沉积型碳酸盐岩地层中发现了新型的风化壳型稀土矿,初步估算稀土资源量已达中型规模,取得了较好的找矿突破,拓宽了找矿思路,值得业界借鉴.通过区域地质地球化学背景和AP00 稀土异常区资料的综合分析,认为AP00 风化壳型稀土矿的形成是经历了4 次不同地质作用逐渐富集成矿的过程,是多因复成型稀土矿.根据AP00 稀土矿的浸出率较低,重稀土Y元素构造(岩浆)叠加成矿作用明显,推断在深部可能存在以钇为主的重稀土原生矿,预示着寻找重稀土矿具有较大潜力.
Abstract
The Ximeng-Lancang area in southwestern Yunnan resides in the southern section of the Nujiang-Lancangjiang-Jinshajiang o-rogenic belt in Southwest China.The 1∶50,000 geochemical soil survey revealed 24 rare-earth-element(REE)geochemical anoma-lies,which are primarily distributed in the Carboniferous Pingzhang Formation mafic volcanic rocks and the Carboniferous-Permian Yu-tangzhai Formation sedimentary carbonate rocks within and near the Changning-Menglian deep fault zone.Furthermore,the AP00 REE geochemical anomalies ranking high in the evaluation were analyzed in detail through a 1∶10,000 geochemical soil survey,a 1∶10,000 special geological survey,and light-duty prospecting engineering in mountainous areas.A new type of REE ores in weathering crusts has been first discovered in sedimentary carbonate strata,with preliminarily estimated REE resources reaching a medium scale,sugges-ting a prospecting breakthrough.This finding shows a new prospecting approach,which can be referenced for similar research.As re-vealed by a comprehensive analysis of the regional geological and geochemical settings and the data of AP00 REE anomalies,the AP00 REE ores in weathering crusts have undergone a gradual enrichment and mineralization process involving four different geological processes,suggesting polygenetic compound REE ores.Considering the low leaching efficiency of AP00 REE ores and significant struc-tural(magmatic)superimposed mineralization of the heavy REE yttrium,it is inferred that yttrium-dominated primary REE ores might exist in the deep part,implying high potential for heavy-REE ores.
关键词
稀土地球化学异常/风化壳型稀土矿/找矿意义/土壤/西盟—澜沧Key words
REE geochemical anomalies/REE ores in weathering crusts/prospecting implication/soil/Ximeng-Lancang引用本文复制引用
出版年
2024
国家科技期刊平台
NSTL
万方数据