扫描仪在岩矿鉴定与岩相学研究中的应用——薄片扫描法

Application of scanner for the rock-mineral identification and petrography——Thin section scanning method

利用偏光显微镜进行岩矿鉴定和岩相学分析是矿物学、岩石学研究的一项基本工作。常用偏光显微镜的观察视域范围狭小,视域大小不能随意变动,这对大视域观察与识别镜下岩石的结构、构造、显微地质现象和粗大矿物等造成困难。基于上述问题,本文在偏光显微镜成像原理基础上,开发出利用扫描仪和偏振光片获取岩石薄片大视域图像的方法,即薄片扫描法。该方法能获得大视域的单偏光和正交偏光图像,为科学研究提供精确的、全面的图像证据资料。薄片扫描法所需设备简单、操作简易、能获得全域精美的数字化图像、能清晰的反映矿物结构构造和地质现象,为识别矿物学和岩石学信息提供了科学方法。薄片扫描法适用于矿物颗粒粗大、形态复杂的显微地质现象,常规偏光显微镜下不能反映结构、构造的样品。薄片扫描法的成功开发,对岩相学、构造岩相学等方面的研究具有现实意义。

The rock-mineral identification and petrographic analysis by using the polarized light microscopy are basic works in mineralogical and petrological researches.The narrow viewing scope of polarizing microscope and its inconvenience in changing visual field size resulted in the difficult to observe and identify the texture,structure,micro-geological phenomenon as well as the large mineral particles of rocks through the polarizing microscope.Taking the above factors into consideration,on the basis of the image forming principle of polarizing microscope,a method to obtain an image of large view of thin section by using scanner and polarizer of microscope,called thin section scanning method,has been developed in this paper.Images of plane polarized light and perpendicular polarized light under microscope with large horizon can be obtained by using this method in order to provide accurate and comprehensive image evidence data for the scientific research.The thin section scanning method is characterized with simple equipment and easy operation procedure.Large view exquisite digital images which show clear mineral textures,structures,and geological phenomena can be obtained by using this method which is a new scientific method for identifying mineralogical and petrological information.The thin section scanning method is suitable for studying samples with micro-geological phenomena of large mineral particles and complicated morphologies,textures and structures which were not capable to be shown using the conventional polarizing microscope.The successful development of thin section scanning method has great practical significance to researches of petrology and structural petrography.