剪切作用对有机质光学各向异性体发育的控制

THE INFLUENCE AND CONTROL OF SHEARING ON THE DEVELOPMENT OF THE OPTICAL ANISOTROPY OF ORGANIC MATTER

湘西泸阳县白沙镇西不远处发育一条含大量凝析油的超浅成脆韧性剪切带。该剪切带中发育了一种光学各向异性体，Ｒｏ，ｍｉｎ＝０．３４－０．８１％；Ｒｏ，ｍｅｄ＝１．０１－１．８４％；Ｒｏ，ｍａｘ＝２．５２－３．２０％，最大双反射率可达８７％。研究表明，光学各向异性椭球体的Ｒ０，ｍａｘ轴的分布与Ｓ面理一致，表明了剪切应力对有机质光学各向异性的发育具有一定的影响和控制。

Not far from western Baisha town of Luyan county in western Hunan, there is a shallow oil bearing brittle ductile shear zone, in which the organic matter has striking optical anistrophy, with R o,min values ranging from 0.34% to 0.81%, R o,med values from 1.01% to 1.84%, and R o,max values from 2.52% to 3.20%, and the maximum bireflectance amounting to 87%, the R o,max axis of the optical anisotropy ellipsoid being paralled to S foliation. The shear stress is considered to have an influence and control on the development of optical anisotropy of the organic matter.