摘要
云南盈江地区广泛分布三叠纪至古近纪等各个时代的酸性侵入岩,岩体中稀土元素丰度较高(ΣREE=117.92×10^-6~645.24×10^-6),风化壳发育广泛,具有较好的找寻离子吸附型稀土矿的前景。利用原岩岩石地球化学、矿体稀土总量、稀土元素浸出率等手段,得知该地区稀土矿含矿原岩为中粗粒二长花岗岩,并多位于其全风化层下部和半风化层上部,负铕异常明显(δEu=0.24~0.42),轻稀土较重,稀土分馏明显(LREE/HREE=7.67~17.70,La N/Yb N=9.66~40.19),或起源于深源,经部分熔融、分离结晶成;离子型稀土元素占比差异巨大,从半风化层底部的4.69%变化至上部全风化层的73.33%,浸出可利用稀土元素以镧钕为主。本文认为盈江地区南部多为低钇富镧钕轻稀土型稀土矿,北部为中钇轻稀土型稀土矿,并呈现出南部稀土总量高于北部、向北有重稀土元素富集的趋势。未来在盈江北东部拉排一带具有较大的找寻重稀土矿的潜力。
Acid intrusive rocks of Triassic to Eogene are widely distributed in the Yingjiang area,western Yunnan Province,which have high abundance of rare earth elements(ΣREE=117.92×10^-6~645.24×10^-6).Meanwhile,weathered crust is widespread in this area,suggesting a good prospect to search for ion-absorption type rare earth ores.Analysis of petrogeochemistry,total REE,and ionic REE leaching rates indicates that the protolith of these ores is medium-coarse adamellite,most of which lies in the lower part of completely-weathered layer or the upper part of the half-weathered layer.Their Eu anomalies are obvious(δEu=0.24~0.42),and fractionation of light REE is higher than heavy REE(LREE/HREE=7.67~17.70,La N/Yb N=9.66~40.19),suggesting that they originated from a deep source which experienced partial melting and fractional crystallization.Proportions of ionic REE vary from 4.69%in the base to 73.33%in the top of weathered layers.Most of those available and recyclable ionic rare earth elements are dominated by La and Nd.It is indicated that there is a tendency that most of those light rare earth ores with low total REE are distributed in the southern Yingjiang area,while those with medium rare earth ores are distributed in the north.There is a high potential of prospecting heavy HREE ores in the northeast of this area.
作者
燕利军
陈永清
邓志祥
陈曹军
严志安
王胜江
梅永辉
杨淑胜
佘中明
YAN Lijun;CHEN Yongqing;DENG Zhixiang;CHEN Caojun;YAN Zhian;WANG Shengjiang;MEI Yonghui;YANG Shusheng;SHE Zhongming(Yunnan Institute of Geological Survey,Kunming,Yunnan 650216;China University of Geosciences(Beijing),Beijing 100083;Yunnan Department of Natural Resources,Kunming,Yunnan 650000)
出处
《地质与勘探》
CAS
CSCD
北大核心
2020年第2期288-301,共14页
Geology and Exploration
基金
云南省地勘基金项目“云南省1∶5万盈江县旧城梁河街河头村矿产地质调查”(编号:D201716)资助。
关键词
稀土矿
风化壳型
离子型稀土元素浸出率
成矿特征
找矿方向
盈江地区
云南
rare earth ores
weathered crust of granite
ionic REE leaching efficiency
metallogenic characteristics
ore prospecting
Yingjiang area
Yunnan Province
