Three Concepts of Fabric Statistics (Curie 1884, Schmidt 1925, and Niggli 1948) and Their Modifications and Elaborations, A Historical Discussion

There are three concepts of fabric statistics: (1) the NEUMANN-MINNIGERODE-CURIE (1884) concept; actually Curie originated the fabric models, based on crystallographic elements of the cause-symmetry, media-symmetry, and effect-symmetry. (2) the SCHMIDT (1925) or SANDER (1930) concept classifies fabric diagrams keyed to rock types and to the kind of deformation, and is based on 5 types of tectonites. (3) the NIGGLI (1948) concept, a general symmetry concept, referring to morphology, which can be applied to all media in the entire field of natural and pure sciences.

All three concepts are typically European. In the 1920's and 1930's some American researchers travelled to Europe to study the techniques of fabric statistics. Among them was Haff (1938) who holds the American priority. Today universal stage research is not very common in the U.S.; instead, macrofabrics are studied by geological compass. In the application of the Schmidt-Sander concept to geological environments, Rueger (1928) of Heidelberg holds the priority.

This paper compares the three concepts, and deals with their developments and elaborations in Europe, in regard to their use in a precise 3-dimensional way, on a thin section scale.