褐帘石是绿帘石族矿物,是轻稀土(LREE)和Th等元素的重要载体矿物(Exeley,1980;Brooks et al.,1981;Gromet and Silver,1983;Tribuzio et al.,1996;Hermann,2002),并且常控制俯冲带流体的LREE和Th的含量以及影响着岩石中微量元素的演... 褐帘石是绿帘石族矿物,是轻稀土(LREE)和Th等元素的重要载体矿物(Exeley,1980;Brooks et al.,1981;Gromet and Silver,1983;Tribuzio et al.,1996;Hermann,2002),并且常控制俯冲带流体的LREE和Th的含量以及影响着岩石中微量元素的演化(如Hermann,2002).……展开更多
本文研究了6个来自不同产状、不同地区的含褐帘石样品,包括4个伟晶岩(M1663来自内蒙集宁益元兴、M7673来自内蒙集宁察汗营地区、M4960来自美国Amherst County Virginia地区、M4976来自挪威Liksviken地区)、2个矽卡岩(M1697产自河北地区...本文研究了6个来自不同产状、不同地区的含褐帘石样品,包括4个伟晶岩(M1663来自内蒙集宁益元兴、M7673来自内蒙集宁察汗营地区、M4960来自美国Amherst County Virginia地区、M4976来自挪威Liksviken地区)、2个矽卡岩(M1697产自河北地区、M1679产自湖南郴县地区)。通过对这6个不同产状褐帘石的电子探针主量、稀土和微量元素分析及拉曼、红外光谱学的研究来揭示褐帘石晶体化学特征。结果表明,褐帘石成分均匀,晶体内发育微裂隙,局部有脉体充填,但不同产状的褐帘石样品在主量元素如Fe O、Ca O、Al_2O_3以及REE如Ce_2O_3、Nd_2O_3、La_2O_3的含量具有明显的差别。其系统的光谱学数据表明褐帘石晶体的特征峰强度和峰位的偏移均与其组分有关,并分析指派了部分光谱峰位的归属,揭示了褐帘石中特殊谱峰位置的迁移与其元素含量、晶体结构之间的关系。拉曼光谱揭示了褐帘石单晶有20组拉曼活性谱峰(ν1~ν20),其中ν2~ν4、ν5~ν8、ν16~ν19谱峰的迁移与A位上的Ca与稀土元素之间置换作用有关;ν10~ν12谱峰是O-Si-O弯曲振动引起,其拉曼谱峰的偏移可能与Si含量有关;ν13~ν14谱峰的迁移则可能是多种元素变化共同作用的结果。褐帘石单晶红外光谱展示了13组红外活性谱峰(a-m),h-k谱峰的偏移与在M1或M3位上Fe^(3+)和Al相互替代而导致的; b-g谱峰的偏移是与硅氧四面体中Si-O非对称伸缩振动有关; OH(l-m)双峰的出现可能与M1、M3位上Fe^(3+)的含量有关。研究结果表明伟晶岩类岩石中褐帘石晶体结构中Fe^(3+)与Al^(3+)间的置换作用强于矽卡岩类岩石中的褐帘石;而矽卡岩类岩石中褐帘石晶体结构中在A位上稀土元素与Ca置换作用则大于伟晶岩类岩石中的褐帘石。展开更多
The granite pegmatite veins and quartz carbonate veins mentioned in this paper occur in a structurally fractured zone in high-grads Archaean gneiss which corresponds tectonically to an anticlinal axis in a geosynclina...The granite pegmatite veins and quartz carbonate veins mentioned in this paper occur in a structurally fractured zone in high-grads Archaean gneiss which corresponds tectonically to an anticlinal axis in a geosynclinal area. The distribution of these veins is prominently controlled by two structural systems striking N 330°--340° W and N 0°--20° E respectively. Allanite, monazite and other rare metal minerals in the veins are related to aegiritization, albitization, microclinization and other alkaline metasomatism, occurring ubiquitously in alkali-metasomatic species and alteration zones. A positive correlation has been found between the rare earth contents of the veins and their K2O/Na2O ratio. During pegmatie and hydrothermal stages, a significant proportion of the rare metals (Ce group) is confined to allanite and etc., while a limited part (Y group) is related to sphene and apatite.展开更多
文摘 褐帘石是绿帘石族矿物,是轻稀土(LREE)和Th等元素的重要载体矿物(Exeley,1980;Brooks et al.,1981;Gromet and Silver,1983;Tribuzio et al.,1996;Hermann,2002),并且常控制俯冲带流体的LREE和Th的含量以及影响着岩石中微量元素的演化(如Hermann,2002).……
文摘The granite pegmatite veins and quartz carbonate veins mentioned in this paper occur in a structurally fractured zone in high-grads Archaean gneiss which corresponds tectonically to an anticlinal axis in a geosynclinal area. The distribution of these veins is prominently controlled by two structural systems striking N 330°--340° W and N 0°--20° E respectively. Allanite, monazite and other rare metal minerals in the veins are related to aegiritization, albitization, microclinization and other alkaline metasomatism, occurring ubiquitously in alkali-metasomatic species and alteration zones. A positive correlation has been found between the rare earth contents of the veins and their K2O/Na2O ratio. During pegmatie and hydrothermal stages, a significant proportion of the rare metals (Ce group) is confined to allanite and etc., while a limited part (Y group) is related to sphene and apatite.
基金supported by the National Natural Science Foundation of China(41402042,41002064,and 42172090)the Natural Sciences and Engineering Research Council of Canada(NSERC)Discovery Grant。