AN ANALYSIS OF THE INTERRELATIONSHIPS OF GRAIN ORIENTATION, GRAIN SIZE AND GRAIN ELONGATION

Authors


ABSTRACT

Textural parameters of seventeen thin sections cut from specimens of neritic units of the Thorold and Grimsby Sandstones (Silurian), were examined. The interrelationships of grain orientation, grain size and grain elongation were found to be as follows:

  • 1The interrelationships among the textural parameters within each sample indicate that the coarser grains (0.24–0.39 mm) are more elongated and their orientations tend to cluster within few preferred orientational classes.
  • 2The interrelationships among the samples, within the same stratigraphic section, whose grain size averages range between the fine to the very fine sand grades, indicate that the average coarser grained samples have non-preferred grain orientations.
  • 3Samples having a wider range (large measured dispersion) of grain sizes and elongations, tend to have weaker preferred grain orientations.
  • 4The type of grain orientation distribution in each sample appears to be more strongly related to the maximum values and measured variabilities, than average values of grain size and elongation.
  • 5Utilizing a multiple regression methodology, it is found that the values of the vector magnitudes per cent of the preferred grain orientation distributions are best predicted if only the averages and standard deviations of grain elongations are taken into consideration.

Ancillary