STUDIES ON GRAIN-SIZE MEASUREMENT METHODS AND THEIR APPLICATIONS
岩石颗粒度测量方法的研究及其应用

The grain size of rocks is an indicator of hydrodynamic conditions of sedimentation and recurrence of hydrochemical conditions in sedimentary stage. Therefore, the accurate measurement of grain size is of great significance for the petrological and microstructural study of rocks. The relationship between grain size of various minerals, grain shape, character of distribution of grain size and environments of rock formation are close. They are indicators of physic-chemical conditions of deposition, contemporaneity, diagenesis and deformation. Three methods for the grain-size measurement, for example, point measurement method, linear measurement method, belt measurement method and two different counting procedures have been illustrated in detail in the paper. The comparison of these three methods has shown that the result obtained from grain number belt measurement method and counting procedure of linear length percentage represents more objectively the actual grain size of sedimentary rocks and sedimentary environment.