首页|滇西那俄花岗伟晶岩型铍矿床矿石矿物的元素组成特征及其成矿意义

滇西那俄花岗伟晶岩型铍矿床矿石矿物的元素组成特征及其成矿意义

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滇西那俄铍矿床是近年评价的小型稀有金属矿床,矿体主要为石榴子石钠长石化花岗伟晶岩脉,赋存于二长花岗岩中.矿体长100~1 150 m,厚度0.43~3.70 m,w(BeO)为0.007%~1.790%,w(Ta2O5)为0.003 2%~0.053 3%,w(Rb2O)为0.041%~0.317%.有用组分以铍矿为主,共伴生钽、铷矿;少数矿石以钽矿为主,共伴生铍、铷矿.矿石矿物以绿柱石、铌钽铁矿、白云母、钾长石为主,区内最明显的找矿标志是含绿柱石伟晶岩,其次是含石榴子石钠长石化伟晶岩.电子探针分析显示:绿柱石属于无碱绿柱石-低碱绿柱石,分子式为Be2.8928~2.9481 Al1.9766~2.0225 Si6 O18;云母中 w(Li2O)为0.500 1%~2.427 9%,w(Rb2O)为0.730 3%~2.304 2%,属白云母—多硅白云母—富锂多硅白云母;钾长石中含有较高的 w(Rb2O),为 0.486 1%~1.033 4%,分子式为 K0.8932~0.9713[Al1.0013~1.0151 Si2.9809~2.9990O8];石榴子石能谱谱系以发育Mn、Fe双峰为特征,以锰铝榴石(Spe)和铁铝榴石(Alm)为主,锰铝榴石体积分数达67.02%~69.07%,属岩浆成因锰铝榴石.本区Be元素主要赋存于绿柱石中,Rb元素赋存于钾长石和白云母中,Li元素赋存于白云母—多硅白云母—富锂多硅白云母中.白云母和绿柱石成分显示那俄地区花岗质岩浆初始Li并不富集,在伟晶岩演化晚期岩浆中高度富集F-Li流体活动是该地区稀有金属异常富集的重要因素.
Elemental Composition and Metallogenic Significance of Ore Minerals in Na'e Granite-Pegmatite Type Beryllium Deposit in Western Yunnan Province
Na'e small pegmatitic beryllium deposit has recently been proved in the western Yunnan Province.The ore bodies are found in garnet and albitite granite pegmatite dikes within monzonitic granite.These ore bodies range from 100-1 150 m in length,0.43-3.70 m in thickness,and contain BeO,Ta2O5,Rb2O in concentrations of 0.007%-1.790%,0.003 2%-0.053 3%and 0.041%-0.317%,respectively.The mainly major useful element in the ore is beryllium,associated with tantalum and rubidium.Some few ore mainly contains tantalum,and associated with beryllium and rubidium.The ore minerals include beryl,niobium tantalite,muscovite and K-feldspar.The beryl-bearing pegmatite is a siginificant prospecting indicator in the area,followed by garnet bearing albionite pegmatite.EPMA results show that beryl falls into the alkali-free beryl to low alkali beryl.The molecular formula for beryl is Be2.8928-2.948i Al1.9766-2.0225 Si6 O18.Muscovite contains w(Li2O)0.500 1%-2.427 9%and w(Rb2O)0.730 3%-2.304 2%,belonging to muscovite-polysilica muscovite-Li-rich muscovite.K-feldspar has a high w(Rb2O)content of 0.486 1%-1.033 4%,with a molecular formula of K0.8932-0.97i3[Al1.0013-1.0151 Si2.9809-2.9990O8].Energy spectrum of garnet is characterized by the development of Mn and Fe bipeaks,mainly spessartine(Spe)and almandine(Alm),with spessartine accounting for 67.02%-69.07%,indicating a magmatic origin of spessartine.Beryllium is mainly occurred in beryl,rubidium in K-feldspar and muscovite,and lithium in muscovite-polysilica muscovite-Li-rich muscovite.The composition of muscovite and berylite shows that lithium was not initially enriched in granitic magmas in the Na'e area,but the late pegmatite evolution involving highly enriched F-Li fluid activity in magmas played an important factor in the abnormal enrichment of rare metals in this area.

Na'e beryllium deposit in western Yunnan Provincepegmatitic beryllium depositgranite pegmatiteberylmicaK-feldspargarnetrare metal deposit

明添学、唐忠、李蓉、何小虎、田素梅、殷伟、覃勇凯、包丛法、李良、杨斯琦、张子军

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云南省地质调查院(云南省地质科学研究院),昆明 650051

自然资源部三江成矿作用及资源勘查利用重点实验室,昆明 650051

云南省三江成矿作用及资源勘查利用重点实验室,昆明 650051

昆明理工大学国土资源工程学院,昆明 650093

云南大学地球科学学院,昆明 650500

云南省核工业二○九地质大队,昆明 650032

云南省国土资源规划设计研究院,昆明 650216

昆明理工大学材料科学与丁程学院,昆明 650093

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滇西那俄铍矿床 伟晶岩型铍矿床 花岗伟晶岩 绿柱石 云母 钾长石 石榴子石 稀有金属矿床

中国地调局项目中国地调局项目云南省地质勘查基金云南省地质勘查基金云南省地质勘查基金

DD20221695DD20190379D202101D202305Y202305

2024

吉林大学学报(地球科学版)
吉林大学

吉林大学学报(地球科学版)

CSTPCD北大核心
影响因子:1.062
ISSN:1671-5888
年,卷(期):2024.54(2)
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