THE WENO AND PAWPAW FORMATIONS OF THE TEXAS 



COMANCHEAN 1 



By W. S. ADKINS 



INTRODUCTION 



The Weno and Pawpaw formations are two thin formations lying near 

 the top of the Comanchean series of strata, and are most typically developed 

 in the region between the Red and the Brazos rivers. The importance of 

 these formations, especially the Pawpaw, is much greater than their thick- 

 ness would seem to indicate. The Pawpaw is a formation of small thick- 

 ness, sharply limited lithologically both above and below, and contains 

 a remarkable series of small pyritic fossils which are so sharply charac- 

 terized and so distinctive in appearance, even in minute fragments such 

 as are encountered in drilling, that this formation should be recognized in 

 wells lying to the east of its outcrop and should furnish at least one certain 

 and dependable stratigraphic level in the Comanchean. In the hope that 

 the formation may have this value, its fauna has been described in some 

 detail and the lateral variations in its lithological character indicated. 2 

 The same statements hold to a lesser extent for the Weno formation. The 

 stratigraphic position of these two formations in the Comanchean series 

 and their equivalents in the Central Texas section are given in the fol- 

 lowing table. 



The Weno and Pawpaw formations are visible over a small areal extent, 

 their outcrops aggregating somewhat more than 100 square miles, mainly 

 in a narrow strip in Johnson, Tarrant, Denton, Gooke and Grayson Coun- 

 ties, Texas, and Love, Marshall, Bryan and Choctaw Counties, Oklahoma. 

 In addition they have stratigraphic equivalents in Central and Western 

 Texas and in Mexico, that will be discussed later. Their north-south dis- 

 tribution in Texas is between Lat. 32N. and 34N. ; and their east-west 

 distribution is practically unknown. In Oklahoma their east-west distri- 

 bution is between Long. 9515' and 97 ; and their north-south distribution 

 is unknown. The total length of their outcrop north of the Brazos River 



'Manuscript accepted June 15, 1920, published November, 1920. 



"It is hoped that operators and others having well samples suspected of being Upper 

 Comanchean will submit them for examination to the Bureau of Economic Geology 

 at Austin. 



3 I wish to express my indebtedness to Professor W. M. Winton, with whom the 

 preliminary work on these and other Comanchean formations was done jointly. The 

 results of these studies will appear in forthcoming papers by both authors. 



