Classification of carbonates

Abstract

Avariety of classification schemes have been proposed for limestones that provide information relating to their origin, component composition, grain size, presence of matrix or cement, and depositional setting. The first universally accepted scheme was that of Folk, developed in 1959 to integrate the origin, component composition, grain size, and depositional setting. This was elaborated further in 1962. Folk’s scheme is most suited for the study of thin sections of limestones. An alternative classification scheme was proposed by Dunham in 1962. This is more suited for limestone descriptions made when using a hand lens or binocular microscope. It was further modified in 1971 by Embry and Klovan. Dunham’s scheme is now commonly used by the oil/gas exploration industry. A subsequent modification was proposed by James in 1984. It enables these various earlier schemes to be used interchangeably. The classification schemes can be represented in diagrammatic form.