中国铍矿成矿规律

中国是世界铍资源大国,本次工作统计到中国铍资源产地241处。铍矿床可分为内生型和外生型。根据岩浆系统的碱铝属性,内生铍矿床可分属于过铝性、偏铝性、过碱性成矿系统;根据流体演化阶段,再分为岩浆型、伟晶岩型、岩浆热液型等3个类型;然后根据赋矿环境进一步分为伟晶岩型、花岗岩型、石英脉型、矽卡岩型、云英岩型等多个矿化形式。过铝性系统的矿石矿物主要为绿柱石;偏铝性系统的矿石矿物主要为硅铍石、羟硅铍石、日光榴石等;碱性系统的矿石矿物主要为硅铍钠石、斜方板晶石、硅钡铍矿、硅铍石、羟硅铍石、硅铍钇矿等。不同赋矿环境产生不同类型的铍矿床,对应不同的矿物组合、矿化分带、矿石结构。统计结果表明,中国铍矿床主要产于过铝性的成矿系统,偏铝性、碱性成矿系统的铍矿床较少。多数铍矿床形成于中生代,主要产于新疆阿尔泰、川西、南岭等成矿带。碱性成矿系统的铍矿床多分布在板块边缘的深断裂或裂谷,过铝性成矿系统的铍矿床主要形成于褶皱造山带,具有一定的定向分布特征。过铝性-偏铝性成矿系统的铍成矿作用可用表示不同岩浆演化阶段和成矿环境的成矿模型描述。笔者建议:在阿尔泰和川西成矿带,重点考虑花岗伟晶岩型锂铍铌钽资源的综合找矿工作;在华南地区,注意与钨锡共(伴)生的铍资源的综合利用;着重在地质找矿和科研工作程度较低的地区,包括在东南沿海、大兴安岭地区寻找火山岩型和岩浆热液型铍矿床;加大西部铍资源空白区的找矿工作。

A Review of beryllium metallogenic regularity in China

China has rich beryllium resources. In this study, 241 mineral occurrences were collected. Beryllium deposits can be classified into endogenous and exogenous types. According to alkali aluminum indexes of endogenous deposits, beryllium deposits can be classified into peraluminous, metaluminous, and alkaline ore-forming systems, and according to evolution of ore-forming fluids, they can be further classified into pegmatitic, magmatic, and hydrothermal deposits; what is more, according to mineral-hosting rocks, they can be classified into pegmatite, granite, quartz veins, skarn, and greisen, volcanic types. Usually, the ore mineral in the peraluminous system includes beryl, the ore minerals in the metaluminous system include phenacite, bertrandite, and helvite, and the ore minerals in the alkaline system comprise chkalovite, epididymite, gadolinite, barylite, phenacite, bertrandite, and some other minerals. Different ore-hosting environments produced different mineralization belts and ore textures. Beryllium deposits in China mainly formed in the peraluminous system, and only a few deposits formed in metaluminous and alkaline systems, which mainly occurred in Mesozoic, and were mainly located in Altay of Xinjiang, western Sichuan, and Nanling. The beryllium deposits of the peraluminous system normally formed in folded orogenic belts somewhat in orientation distribution, but the deposits in the alkaline system normally formed in a rift or continental extensional environment. A model can describe the ore-forming environments of beryllium deposits of peraluminous and metaluminous systems. The authors hold that the rare metal resources incluiding beryllium should be explored in granitic pegmatite comprehensively in Altay and western Sichuan, the paragenetic or associated beryllium in W-Sn deposits should be utilized comprehensively, and in the areas with insufficient work, especially in southeast coastal area, Da Hinggan Mountains and Sanjiang area of southwestern China, specially attention should be paid to the research on volcanic type and magmatic hydrothermal type beryllium deposits.