The Devonian system became established in North America in 1847 through the writings of Verneuil, whose views were made known largely by Hall’s translation. In 1851 Hall accepted the Devonian system and the European arrangement of it. Since then the system has been elaborated and expanded by the addition of the Helderberg stage. In this century a few correlation charts have been prepared (Ulrich, 1911; Schuchert, 1910; Shimer, 1934), but none considered Devonian rocks in detail. The present chart is therefore the first comprehensive one to be offered.
This chart has been compiled by the writer with the help of several colleagues and the close guidance of Dr. Edwin Kirk. Cooper is mainly responsible for the arrangement of the Middle Devonian and the Devonian of parts of western United States and of Gaspe, Quebec. Swartz arranged the Lower Devonian columns of the Appalachians, Butts advised on . . .