雅江残余盆地南北缘伟晶岩稀有金属矿地质特征

Geological Features of Pegmatite Rare Metallic Deposit in the Southern and Northern Margins of the Yajiang Residual Basin

雅江残余盆地伟晶岩稀有金属矿床的形成,与其地质构造环境、伟晶岩脉形成机制、伟晶岩脉类型有密切关系。北缘甲基卡地区主要受印支末期—燕山早期构造岩浆热隆事件影响,伟晶岩脉成群成带发育,形成大型、超大型锂稀有金属矿,南缘打枪沟地区缺乏岩浆热穹窿构造,仅表现为岩浆期后花岗伟晶岩残余熔浆分异演化,沿岩体内外接触带发育低类型伟晶岩脉,以铍矿化为主,兼有锂矿化。

Ore-formation of the pegmatite rare metallic deposit in the southern and northern margins of the Yajiang Residual Basin was in close relation to geological structural setting and pegmatite type and its genetic mechanism. Pegmatite dykes were developed in group at Jiajika in the northern margin of the Yajiang residual basin, where superlarge and large Li and rare metallic deposits were formed thanks to the late Indo-Sinian and early Yanshanian tectonic-magmatic thermal dome event. While evolution of granitic pegmatite magma was responsible for pegmatite characterized by Be mineralization dominating over Li mineralization due to for lack of thermal dome event in the southern margin.