A New System for the Cataloguing and Storage of Sedimentary Rocks Based on Lithologic and Genetic Characteristics

Abstract

ABSTRACT A system for the identification, cataloguing, and storage of rocks should have certain attributes, namely, it should be expansible and rocks of the same or similar identity should have related catalogue designators. The catalogue designators should also be usable for rock thin sections and other kinds of investigation data such as that acquired on heavy minerals. The writers have developed a method of cataloguing sedimentary rocks according to type, structures, textures and associations based largely on F. J. Pettijohn's (1957) treatment of sedimentary rocks. For example, conglomerates and breccias are designated P1, quartzose and volcanic arenites P2. Orthoquartzites carry a P21 designator. A first cycle orthoquartzite would be catalogued P211At. The capital A represents the first sample of this rock type to be catalogued and the lower case t indicates that a thin section has been prepared for the rock. Additional specimens of this type from other formations would be designated with successive letters of the alphabet. If several samples are collected from the same formation but from different localities, each locality designation is represented by a number or numbers following the letter or letters designating the formation. Serial samples from the same formation and locality would carry lower case letters following the last figure of the designator. A sample of the Flathead (Cambrian) orthoquartizite for example, might be designated P211A. Another sample of this formation from a different locality would be numbered P211A2. If a series of samples were collected at this latter locality they would be designated P211A2a, P211A2b and so forth. Two records of each specimen may be kept with the principal record maintained on serially organized 3 5 cards. Another record, a single line listing of pertinent data on each specimen is desirable but not necessary.