摘要
五台山早前寒武纪变质岩中的白云母属二八面体的2M型多型变体,其中五台群中的白云母为富含绿鳞石分子的普通白云母,滹沱群为多硅白云母。通过对这些白云母化学成分和b_0值测定,确定五台群变质条件属中低压相系,滹沱群属中高压相系。五台群绿片岩相的变质压力为0.3—0.5 GPa,滹沱群为0.5—0.6 GPa。基于白云母成分和b_0值的研究,对划分变质级别、变质类型;确定变质作用期次;进行地层对比和构造分析等方面是可行的。
The muscovites from Precambrian metamorphic rocks in Wutai Shan belong to the 2M-polytype of dioctahedrom: those from Wutai group are common muscovites rich in celedonite and those from Hutuo group are phengite. By measuring the chemical composition and b_0 value of the muscovites,it is determined that the metamorphic conditions of Wutai group belongs to midlow pressure phase series and that of Hutuo group belongs to mid-high pressure phase series. The matamorphic pressure of greenschist phase of the Wutai group was of 0. 3-0. 5 Gpa and the Hutuo group of 0. 5-0. 6 Gpa. Based on studying the chemical composition and b_0 values of muscovites, it may help to determine the metamorphic grade and type,the metamorphism stage and work on the strata correlation and the regional structural analysis.
出处
《矿物岩石》
CAS
CSCD
1993年第2期1-8,共8页
Mineralogy and Petrology
关键词
早前寒武纪
五台群
白云母
变质岩
Wutai Shan Hinterland
Precambrian
Wutai group
Wutuo group
muscovite
