中国花岗伟晶岩的研究历程及发展态势

History of granitic pegmatite research in China

我国是稀有金属资源大国,产出了众多独具特色的稀有金属花岗伟晶岩矿床。国内外学者对这些花岗伟晶岩的研究较大地促进了世界伟晶岩理论的发展。在世界伟晶岩研究历程中,虽然有学者认为伟晶岩形成于热液交代作用,但从较早的Jahns-Burnham模型,到后来的London提出的岩浆非平衡结晶模型和Thomas提出的岩浆液态分离模型,都强调了岩浆分异作用对于伟晶岩形成的重要性。我国花岗伟晶岩研究继承于苏联科学家的伟晶岩理论,并逐渐与国际接轨,在对阿尔泰、川西等地区典型花岗伟晶岩的研究过程中,提出了基于云母和长石的花岗伟晶岩分类方案;发展出变质分异型、超变质分异型和重熔岩浆分异型等伟晶岩成因模型;建立了指示高分异伟晶岩熔体-流体演化的矿物标型特征;通过对伟晶岩中富晶体包裹体的深入研究,揭示出我国典型花岗伟晶岩形成于较高温压条件的特点;同位素定年和示踪技术的发展,提升了对我国伟晶岩时空分布和物质来源的认识程度。在今后,我国应该重视矿物学、成矿流体、高温高压实验研究,重视稀有金属伟晶岩的综合绿色开发利用,揭示典型伟晶岩的形成机制,创新伟晶岩成岩成矿理论,实现我国稀有金属资源找矿行动和资源开发利用的进步。

China is enriched in rare metal element resources and hosts many unique rare metal granite pegmatite deposits,attracting many pegmatite scholars to investigate the pegmatite-forming mechanism.Over past decades,several mechanisms have been proposed for pegmatite formation ranging from hydrothermal metasomatism in the early Jahns-Burnham model to the later magma non-equilibrium crystallization model proposed by London,and the magma liquid immiscibility proposed by Thomas.The research on granite pegmatite in China has inherited the theory of pegmatite by Soviet scientists and has gradually accepted the western pegmatite theory.In China,during the research on the typical pegmatites(e.g.,the pegmatites in Altai and western Sichuan),granitic pegmatite classification,based on mineral assemblages of mica and feldspar,was proposed.Chinese scholars also built the genetic models of pegmatites,including the fractionation of metamorphic fluid,super-metamorphic melt,and remelted magma,and established mineral typomorphic characteristics to indicate the evolution of highly-differentiated pegmatite.Their research on the crystal-rich inclusions in pegmatites investigated the P-T conditions of pegmatite formations.Isotopic dating and tracing technology has provided a clearer picture of temporal and spatial distribution,and material source of pegmatites in China.Future research should focus on mineralogy,ore-forming fluids,high-temperature and high-pressure experimental research.Analyzing this data will provide an overview of prospects of comprehensive utilization of rare metal elements in pegmatites,investigate the formation mechanism of typical pegmatites,innovate pegmatite diagenesis and mineralization theories,and promote rare metal resources prospecting and utilization progress.