BIOTITES FROM GRANITIC ROCKS OF CENTRAL SIERRA NEVADA BATHOLITH, CALIFORNIA

被引:143
作者
DODGE, FCW
SMITH, VC
MAYS, RE
机构
[1] U. S. Geological Survey, Menlo Park, CA
[2] U. S. Geological Survey, Denver, CO
关键词
D O I
10.1093/petrology/10.2.250
中图分类号
P3 [地球物理学]; P59 [地球化学];
学科分类号
0708 ; 070902 ;
摘要
Biotites from plutonic recks of the central Sierra Nevada and Inyo Mountains, California, have been examined and characterized by powder X-ray diffraction and optical and chemical methods.Compositions of the biotites define a trend in the compositional triangle Fe+3 Fe+2Mg. When related to the experimentally studied ternary system KFe3+3AlSisO12H-1-KFe3+2 AlSi3O10(OH)2-KMg3AlSi3O10(OH)2 and coupled with the estimated positions of biotite solid solutions for different oxygen buffers, the trend suggests that oxygen fugacities in magmas during biotite crystallization were slightly higher than those defined by the Ni-NiO buffer. The compositional data also suggest that magmas were 'buffered' with respect to oxygen by oxides existing within the magmas themselves.Correlation between the Fe/(Fe+Mg) ratio, an inferred temperature indicator, and other elements is generally poor, which suggests that factors other than temperature at the time of crystallization exerted an important influence on compositions. © 1969 Oxford University Press.
引用
收藏
页码:250 / &
相关论文
共 42 条