Abstract
In this article, genetic relations between various types of " graywackes " were investigated synthetically. Several properties which have been pointed out by many workers as the characteristics of "graywackes ", and their meanings, were cited first. Several concepts such as provenance factor, textural and mineralogical maturity, mechanism of transportation (fluidity factor), and " three critical environments of deposition" mentioned by RICH, were summarized in their mutual relations, The origin of variety of "graywackes" was then explained successfully using the above concepts or ideas as shown in the schematized models of Figure 4. Post depositional alteration or diagenesis was mentioned in connection with the origin of clay matrix of graywackes.
