Apparatuses and method for paleocurrent direction determination using reflected light

Method of determining paleocurrent direction of a sedimentary multiple grain structure, said structure represented by a multiple grain sample with a polished surface, comprising the steps of:

• (a) measuring the variations in the intensity of a beam of light from a laser while said sample is at different angular positions relative to said beam and said beam is being reflected from a surface of said polished sample and while said beam of light intersects said surface at Brewster's angle, the reflected ray having a minimum intensity when the average optic axis of the sample lies in the plane of incidence of said beam from said laser,
• (b) determining the direction of minimum intensity of said ray relative to the orientation of said sample from which said sample is taken and thereby determining the paleocurrent direction of said structure.

Apparatus for anisotropic mineral grain orientation comprising, in operative combination, a laser beam generator, photo sensitive means, a rotatable specimen support table, a flat surface specimen on said support, a quantitative light intensity recorder, a drive mechanism for said recorder with movement means therefor controlled by the movement of said table and recording means of said recorder controlled by the photo-sensitive means, an adjustable support for said laser beam generator, said specimen comprised of a plurality of anisotropic grains each elongated parallel to its optical axis, said laser beam directed at the surface of said specimen at Brewster's angle relative to said surface, said laser beam having a greater diameter than the individual length of said grains.