MICROSTRUCTURAL TECHNIQUES IN STUDY OF PHYSICAL PROPERTIES OF ROCK

Techniques have been developed to further understanding of rock behavior in terms of its microstructure. The techniques measure certain fabric parameters on rock discs and in thin sections with the petrographic microscope, for correlation with physical property laboratory tests. They include (a) diametric mineralogical analysis, (b) defect analysis, (c) grain elongation analysis, (d) macro-grid analysis, and (e) transgranular-intergranular analysis. Pulse velocities and breaking strengths in samples of granite and limestone are compared with their fabric properties obtained through these techniques. Examples of such comparisons include the influence of feldspar and quartz abundance in Salisbury Granite on longitudinal pulse velocity, the tendency for the frequency of microscopic defects to be inversely proportional to breaking strength in Barre Granite, the proportionality of average grain size parallel with foliation to breaking strength in Yule Marble, and the inverse proportionality of the ration of transgranular to intergranular failure to breaking strength in Tennessee marble. © 1969.