钠长花岗岩-H_2O-HF体系相关系及含黄玉花岗质岩石的成因  

Phase Relations in the Albite Granite H2O-HF System and the Genesis of Topaz-bearing Granitic Rocks

作　　者：熊小林[1] 朱金初[2] 饶冰[2] 赖鸣远[2] 

机构地区：[1]中国科学院广州地球化学研究所,510640 [2]南京大学地球科学系,210093

出　　处：《地质论评》1999年第3期313-313,共1页Geological Review

基　　金：国家自然科学基金(编号49603048;49473181);南京大学内生矿床成矿机制研究国家重点实验室资助

摘　　要：在P=100MPa,t=840～450℃条件下,通过钠长花岗岩-H_2O-HF体系相关系实验获得:①随体系F含量的增加,固相线温度显著下降。②石英和黄玉的温度稳定域上限升高,碱性长石的温度稳定域上限降低;在F≤4％时,体系能在固相线之上结晶出典型的黄玉花岗岩矿物组合;在F=6％时,体系能在固相线之上结晶出典型的黄玉云英岩矿物组合。③含氟浅色花岗质熔体具有能分异出极端富F残余熔体的趋势。这些实验结果为黄玉花岗岩和黄玉云英岩的低温岩浆成因提供了可靠的实验依据。Phase relations were experimentally determined in the albite granite-H2O-HF system with 2%, 4% and 6% fluorine at 100 MPa and 840-450℃. The results show that:① With increasing fluorine content in the system, the solidus temperatures decreased obviously.② The maximum temperature of the quartz and topaz stability field increased with increasing F content , whereas that of alkali-feldspar decreased. The typical mineral assemblage of topaz granite was stable above the solidus at F≤4 % , and that of topaz greisen was stable above the solidus at F =6%.③The residual melt with a higher F content can be formed by fractional crystallization of a leucogranitic melt with a lower F content. These experimental results provide reliable evidence for the formation of topaz granite and topaz greisen at low-temperature magmatic conditions.

关 键 词：钠长花岗岩-H_2O-HF体系 实验 含黄玉花岗质岩石 

分 类 号：P588.121[天文地球—岩石学]