| 燕利军.滇西梁河县新发现那俄铍矿岩石地球化学特征及铍成矿事件[J].地质与勘探,2021,57(4):739-750 |
| 滇西梁河县新发现那俄铍矿岩石地球化学特征及铍成矿事件 |
| Petrochemical characteristics and metallogenic process of the newly discovered Na’e beryllium deposit in the Lianghe area, western Yunnan Province |
| 投稿时间：2020-11-30 修订日期：2021-03-20 |
| DOI：10.12134/j.dzykt.2021.04.003 |
| 中文关键词: 伟晶岩型铍矿 岩石地球化学 U-Pb年代学 早白垩世岩浆岩 那俄铍矿 梁河县 滇西 |
| 英文关键词: pegmatite vein type beryllium deposit, petrogeochemistry, U-Pb geochronology, Early Cretaceous granite, Na’e beryllium deposit, Lianghe County, western Yunnan Province |
| 基金项目:云南省自然资源厅地质勘查基金项目“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 |
|
| 摘要点击次数: 1507 |
| 全文下载次数: 549 |
| 中文摘要: |
| 滇西新发现的那俄铍矿是一含绿柱石岩浆热液伟晶岩脉型铍矿床，矿体产状多数为北东-南西向延伸，延伸走向长50~1220 m，厚度0.36~3.70 m，品位0.045%~1.79%，并伴生有铌钽铷等多种稀有金属。该矿床围岩主要为二长花岗岩、石英二长闪长岩等。二长花岗岩类SiO2=65.02%~73.65%，Al2O3=13.27%~16.80%，K2O/Na2O=1.18~2.07, A/NCK=1.05~1.15，表现出高硅、富碱、低镁铁的特点；石英二长闪长岩（花岗闪长岩）类SiO2=51.03%~65.88%，Al2O3=15.97%~18.56%，K2O/Na2O=0.57~0.86，A/NCK=0.83~1.10；花岗伟晶岩SiO2=75.16%，Al2O3=13.52%，K2O/Na2O=1.39，A/NCK=1.08，δEu＝0.13~0.36，分异指数＞85，与围岩差异较大，认为那俄铍矿为岩浆热液演化晚期分异结晶形成。研究区所在的勐养岩体锆石U-Pb年龄127.9±1.0~115.2±1.1 Ma，均为早白垩世。通过对研究区的区域大地构造演化、岩石地球化学和U-Pb年代学特征研究后认为，那俄地区在早白垩世经历了早期陆内应力调整期、中期构造活跃期、晚期岩浆热液成矿期三个差异明显的构造-岩浆阶段，而那俄铍矿的形成则是晚期岩浆热液作用的结果。 |
| 英文摘要: |
| The Na’e beryllium deposit is a newly discovered beryllite-bearing pegmatite vein type deposit which is closely related to magmatic hydrothermal fluids. The beryllium ore bodies are about 50~1220 m long，0.36m to 3.70m thick, mostly trending in the NE direction, with ore grade between 0.045% and 1.79%, associated with many rare metal elements such as Nb, Ta, Rb and Cs. The wall rocks of this deposit are mainly monzogranite and quartz monzogranite. The monzogranite contains SiO2 about 65.02%~73.65%, Al2O3 13.27%~16.80%，K2O/Na2O1.18~2.07 and A/CNK 1.05~1.15, characterized by high silicon, rich alkali and low magnesium and iron. The granodiorite contains SiO2 about 51.03%~65.88%, Al2O3 of 15.97%~18.56%，K2O/Na2O 0.57~0.86 and A/CNK 0.83~1.10. The granite pegmatite has SiO2 75.16%, Al2O3 13.52%，K2O/Na2O 1.39, and A/CNK 1.08; with values of δEu 0.13~0.36, and the differentiation index greater than 85, which is quite different from that of the surrounding rocks. It is considered that the Na’e beryllium deposit was formed by differential crystallization in the late stage of magmatic hydrothermal evolution. Zircon U-Pb ages of the Mengyang pluton in the study area range from 127.9±1.0 Ma to 115.2±1.1 Ma, belonging to Early Cretaceous time. Combined with regional tectonic evolution, petrochemistry and U-Pb geochronology of the study area, research suggests that the Na'e area experienced three distinct tectonic magmatic stages in Early Cretaceous time, i.e., the intracontinental stress adjustment, tectonic active period and magmatic hydrothermal mineralization, and the formation of this deposit was the result of the late magmatic hydrothermal process. |
|
查看全文
查看/发表评论 下载PDF阅读器 |
| 关闭 |
|
|
|
