攀西地区长石的X射线研究

本文对四川攀枝花—西昌（即攀西裂谷）地区各个不同时期、不同产状、不同岩类中的斜长石、碱性长石进行了X射线研究,配合单矿物化学分析、电子探针成分分析,结合红外光谱、光学测定,精确地计算了42个斜长石,60个碱性长石的晶胞参数,求出其四个四面体的Al含量,确定长石的成分和结构态。为探索攀西地区岩浆活动演化规律,研究攀西裂谷形成、发展及其消亡历史提供了客观依据。

THE X-RAY STUDY OF THE PLAGIOCLASES AND ALKALI- FELDSPARS FROM PANXI AREA

During the X-ray study of 42 Samples of Plagioclase and 60 samples of alkali-feldspar from Panzhihua-Xichang area ( Panxi rift) Sichuan province we have used X-ray powder diffraction data to accurately calculate the cell parameters of the specimens, thus the Al-Si distributions among the four nonequivalent tetrahedral sites (i.e. the Al-content in T1o, T1m, T2o, T2m of the feldspars) , and the chemical compositions and structural states are determined. It is in agreement with the results derived from chemistry, electron microprobe, optic and infrared spectrum analyses. In this paper, we have also discussed the genesis of the feldspars, it will be helpful to understand the history of formation, development and termination of Panxi rift.