Microphotometric determination of preferred orientation in undeformed dolomites

Preferred orientation was observed in certain undeformed dolomites with a microphotometric technique. The preferred direction of the c-axis was found to be perpendicular to the bedding planes. The degree of orientation is rather slight, but is considered significant due to the fact that thousands of crystals are included in each measurement. It is suggested that the preferred orientation was acquired during an early diagenetic stage of dolomitization, when the individual crystals could rotate and adjust their position so that their maximum cross section tended to lie horizontally.