Geologic chronology had its beginning in north Germany in the superposed formations of Lehmann (1756) and Füchsel (1762), which are now included under the terms Permian and Triassic. Werner (1775–1817), whose knowledge of the geographic distribution of formations was exceedingly limited, did not hesitate to say that they were universal, and that what was true of Saxony held for the entire world. This very erroneous idea of universal formations was destined to sway all subsequent stratigraphy, and it can not be said that geology has yet freed itself wholly of Werner’s dictum. Formations as now understood are more or less localized deposits of sediments or solution materials, and even in the sense that the term was understood by Werner—that is, as of period value—it is not true that they are universal. To emphasize this, we need only contrast the remarkably extensive . . .