Michael R. Sandford

TL;DR: In this article, the authors developed preliminary conclusions concerning the controls on intrinsic mechanical anisotropy of brittle slate. But their preliminary conclusions were based on the assumption that the cleavage orientation was independent of the principal stress difference in the rock.

TL;DR: In this article, the Griffith theory was examined by allocating the orientation distribution of clay mineral basal planes (determined by X-ray texture-goniometric methods) to an assumed equivalent distribution of pre-existing cracks in the rock.

TL;DR: In this article, it was shown that the pole figure generated by the basal planes of illite in Penrhyn slate can be adequately described in a mathematical sense through the use of a particular spherical harmonic function.