ABSTRACT

The study of indistinct structures in consolidated limestones is made possible by use of simple photographic techniques. A cut limestone slab is polished on one side and photographed under alcohol. By use of different film types the structures in the rock can be accentuated or subdued to give required results. A three-dimensional idea of the structures in the limestone can be obtained if an orientated block is sawn into a brick and polished on each side. All six sides are then photographed under alcohol. The prints of the sides are glued together to form a three-dimensional photographic model of the limestone block. Photographs of the model may be taken from any desired angle to give three-dimensional illustrations of the structures in the limestone. A pictoral model of the block can lso be made by tracing the outline of the required structures in ink, and then removing the photographic emulsion with the aid of a bleaching agent.

The method described is not only useful for displaying indistinct structures in limestones, but is also useful for a three-dimensional illustration of different sedimentary structures, attitudes of fossils, and trace fossils.