This report attempts to correlate the outcropping rocks in the type locality of the Detroit River group with the thick sequence of rocks that has been explored by many drilled wells in the Michigan Basin during the last twenty years. The surface nomenclature as recently revised (Ehlers, 1950) is suggested for the subsurface section in place of the heterogeneous collection of names now used. The present work revises earlier reports by the writer (1945, a, b, c).
During the preparation of this report the samples have been examined from more than 300 wells and cores from 9 wells. The writer has also drawn upon the work of Enyert (1949) who wrote a Doctoral thesis on the sandstones of the Detroit River group, and upon Master's theses on various phases of Detroit River stratigraphy written by Cooley (1947), Saunders .(1948), and Tharp (1944). Finally the writer has had the advantage of many consultations in office and field with George V. Cohee of the U. S. Geological Survey, Professors G. M. Ehlers and E. C. Stumm of the University of Michigan, and with other geologists of Michigan and Ontario, especially George D. Lindberg (Sun Oil Company, Toledo), E. J. Baltrusaitis and K. A. Gravelle (Gulf Refining Company, Saginaw), Willard A. Sanger (Pure Oil Company, Clare), Joseph Lindsay and George WinSton (Carter Oil Co. , Grand Rapids), and Charles S. Evans (Union Gas Co. , Chatham, Ontario). It is a pleasure to acknowledge the help received from these geologists and to thank them for it.
The surface and subsurface sections through the Detroit River group in Canada are not included in this report.
