The use of an XY recording microdensitometer and computer permits quantitative and automatic analysis of the crystal orientation patterns determined by the Starkey method. Three computer programs are used. Program REDUCE is specifically to interpret the X-ray diffraction photographs. Correction factors for background and absorption can be applied and the equivalent reflected and transmitted diffracted intensities can be used to normalize the data. The orientation pattern of the selected lattice plane is computed, plotted on a Lambert Equal Area, lower hemisphere projection.The remaining two computer programs are applicable to any orientation pattern represented in spherical projection. The first, CONTOUR, contours the data on the projected hemisphere. The data may be rotated prior to contouring. Program PREDICT enables the orientation of any crystallographic direction to be predicted from one or more measured orientation patterns.The procedure is illustrated by the analysis of quartz orientation in a quartzite from Bergsdalen, Norway.

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