The influence of grain‐selection on the meaning of quartz‐diagrams

The most important factor which would reduce confusion in fabric analyses is the expanded use of partial diagrams. The purpose of this paper is to stress the significance of partial diagrams in a consideration of some confusing aspects of petrofabrics.

Any statistical study results in the accumulation of a mass of detail. In quartz‐fabric analyses the detail consists of the measuring and plotting of thousands of quartz‐axes; in an analysis of joints it consists of the measuring and plotting of thousands of joint‐attitudes. In each case limiting factors are required to give meaning to the accumulated data. The study of joints, to be significant, must be confined to an area with well‐integrated structural features. In quartz‐fabric studies discrimination between grain‐types is essential to the development of interpretable diagrams.