ABSTRACT
Statistics and graphing are subjects which overlap very significantly. This chapter deals with graphs in which each data item is plotted as a point on a suitable piece of graph paper. A simple x - y graph has two axes, at right angles to each other, representing two different quantities. The chapter illustrates a graph which plots sediment density against depth in a well. Each point represents a specific measurement of depth and density. The chapter deals with the problem of plotting data measured on the surface of a sphere on to a flat sheet of paper. This problem occurs, for example, in map making when it is necessary to represent a large portion of the earth's surface by a map in an atlas. The chapter deals with three very similar methods which are widely used in structural geology, crystallography, earthquake seismology and many other branches of earth science.
