On the orientation of discontinuities on rock sample sections

The problem of the distribution of the length of the discontinuity traces visible on plane sections of rock samples is discussed. In terms of mathematics, the problem has been reduced to inhomogeneous Fredholm's integral equation of the 1st kind, in which the known function r(beta) is the distribution density of normalized total length of the projections of discontinuity traces on a straight line with the orientation beta belongs to [ -pi/2 , +pi/2 ]. The method of solving Fredholm's equation has been illustrated on an example.