Classification of Permian Rocks of Western Texas by a Versenate Method of Chemical Analysis

Abstract

There is much confusion regarding the classification of the more common carbonate rocks of the limestone-dolomite series and the combinations of these with silt or clay. A modification of Pettijohn's quantitative scheme is applied to Permian rock samples by the use of a versenate method of chemical analysis. In the Permian rocks of the Malone Mountains, the Black Brecciated limestone is actually a dolomite and the Buff limestone a mixture of calcitic dolomite, dolomite, and dolomitic limestone. Likewise, some of the rocks in the Permian system of the Finlay Mountains that have been called limestones are in reality dolomitic limestone, while certain shales are consolidated dolomitic limestone marls.