COMPOSITION PLOTS IN A TRIANGLE FOR THE CLASSIFICATION OF SANDSTONES BY MICROSOFT EXCEL
HUANG Si jing, HUANG Yu (Chengdu University of Technology, China)
The triangle for the classification of sandstones and composition plots is very important and in common use in sedimentary petrology, but it is very difficult to plot, especially when the data are very large. This paper provides a new method for compositional plots on the triangle for the classification of sandstones by Microsoft Excel. This method is very convenient for use. The plotting steps are as follows: (1) set up a coordinate system (taking F point as an origin) and calculate coordinates of key points of the triangle; (2) graph the classification triangle using the coordinates of key points by means of the function of 2D plot of Microsoft Excel; (3) calculate the coordinates( x values) of samples based on their compositions of Q, F and R contents using the formula ofx=50-50-100- FF+R×100-Q 100 and (4) plot the compositions of Q, F and R on the triangle according to their coordinates calculated.
【CateGory Index】： P631