四川省大渡河下游峨眉山玄武岩夹层中绿鳞石的研究

产于四川省铜街子电站玄武岩沉积夹层中的绿鳞石,具有二八面体1M云母结构,与海绿石结构相似,但以其八面体层中的高Mg含量与海绿石相区别。该绿鳞石是玄武岩两次喷发间断中,凝灰物质沉积后经蚀变而成。

STUDY ON CELADONITE FROM SEDIMENTARY INTERCALATION IN EMEISHAN BASALT AT LOWER REACH OF DADUHE RIVER, SICHUAN PROVINCE

The celadonite studied in this paper was +aken from a sedimentary intercalation in Emeishan basalt at the lower reach of Daduhe River, Sichuan Province. The crystal structure of this celadonite is dioctahedral IM mica structure similar to glauconite structure. The characteristics of crystal chemical is as follows: tetrahedral Si is between 3.70-4.00 and tetrahedral Al is between 0.00-0.30, but tetrahedral Al which replaces Si in glauconite is more than that in celadonite. The octahedral Mg in celadonite is about 0.65, which is much more than that in glauconite. Eurthermore, amount of octahedral Mg increases with decreasing amount of octahedral Al. It is inferred that there are two forms of continuous series which are well developed in chemical characteristics of celadonire and glauconite.The celadonite in sedimentary intercalation was formed by alternation of overlying basalt flow.