摘要
钾长石的2V和N_g∧⊥(010)、N_g∧⊥(001)的夹角是结构状态的函数,能够表明T_1四面体上Si-Al的有序度,具有重要的地质意义。在砂薄片上选取近于垂直a轴(近于垂直锐角等分线N_p)的钾长石碎屑,具有易于判定消光位的干涉色,取得清晰的干涉图象。在费氏台上用锥光法和四轴法能精确测定这些光学数据。此方法操作简便,精度可靠(误差在2°以内),是一种好的光学方法,值得推广。
The 2V and angles NgΛ⊥(010), NgΛ⊥(001) of potash feldspar are a function of its structural state, which can indicate the degree of order of Si-Al in T_1 tetrahedron, of great geological significance. Selecting the potash feldspar clast perpendiular to a-axis in the detrital section (approximately perpendicular to acute bisectrix), it is easy to determine the interference color of the extinction direction and obtain a clear interference figure. Such optical data can be accurately determined in the universal stage by conoscopic method and four-axis method. This procedure is easy to operate with reliable accuracy (with an error of less than 2 degrees), which is proved to be an excellent optical method, worthy spreading.
出处
《湖南地质》
1989年第2期56-60,共5页
Hunan Geology
关键词
钾长石
费氏台
砂薄片
有序度
Universal stage
Detrital section method
Potash feldspar
Structural state
Degree of order
Triclinicity
