Correlation of the outcropping cretaceous formations of the Atlantic and Gulf Coastal Plain and trans-Pecos Texas

This is Number 9 of a series of correlation charts prepared by the Committee on Stratigraphy of the National Research Council, which will cover the post-Proterozoic sedimentary formations of North America. For general information about the project the reader is referred to the general introduction preceding this paper.

The senior author, Lloyd W. Stephenson, is responsible for that part of the chart treating of the Upper Cretaceous series in the Atlantic and Gulf Coastal Plain (exceptions noted below) and the Lower Cretaceous series of the North Atlantic Coastal Plain; with respect to the Upper Cretaceous his presentation is based largely on his personal knowledge of the paleontology and stratigraphy of the area, gained from field and laboratory studies ranging from reconnaissance to detailed; all published information has been considered, and much of it utilized, but it is not practicable to include a complete bibliography. References are given to papers presenting views differing from those of the author, and to recent papers not yet listed in bibliographies. A complete bibliography of Texas geology through 1932 is given by Sellards (1933, p. 819-965). Watson H. Monroe has collaborated in the preparation of that part of the chart showing therelations of the Upper Cretaceous units in Alabama and Mississippi. The classification shown in the Upper Cretaceous part of the Delaware column is based on a recently published paper by Charles W. Carter (1937, p. 237-281). Philip B. King is responsible for the remainder of the chart covering the Lower Cretaceous (Comanche series) of central Texas (largely compiled from published sources) and all of the Cretaceous in trans-Pecos Texas (from personal knowledge and published sources). In March 1941 this part of the chart was checked by R. W. Imlay, and changes were made by King at his suggestion. References to the more important literature are given.

In a correlation chart of this kind, in which age equivalencies are expressed by horizontal lining, it is obviously impossible to indicate relative thicknesses by vertical spacing. Hiatuses are indicated by vertical lining. The red-line overprint is intended to indicate certain important lithologic and faunal boundaries, and to assist the eye in recognizing the age relationships of the geologic units