Weno and Pawpaw Formations 25 



West Texas they are reported as far north as Bailey County, and they 

 are common in Coke and Runnels counties. In Trans-Pecos Texas, the 

 Texas and Pacific Railway roughly divides the southern rudistid facies 

 of the Edwards from the northern littoral facies. The rudistids are 

 rare or wanting at Cerro de Muleros, Kent, Sierra Blanca and the Finlay 

 Mountains ; and present at points between these and the Rio Grande. Gabb 1 

 describes from the Sierra de las Conchas near Arivechi, Sonora, fossils 

 which if correctly identified include among diverse stratigraphic levels 

 that of the Edwards limestone ; the facies represented is unknown to me. 

 Felix and Lenk'- also record the great extent of the Fredericksburg reef 

 facies in Mexico. 



WENO AND PAWPAW FORMATIONS 



The influence of the underlying syncline on the deposition of these two 

 upper Washita formations is small, due to their small thickness. However, 

 they show an appreciable syncline in the Fort Worth region, and a con- 

 spicuous thinning southward. 



Since the maximum rate of change of thickness, like the maximum 

 change in lithology, may not coincide in direction with the outcrop, the 

 formation along the outcrop will in general show only a greater or less 

 north-south or an east-west component of change in thickness or lithology 

 and the maximum change will be in a direction lying at an angle to the 

 outcrop. 



THICKNESS CHANGES 

 North-South Changes 



This is true of the north-south outcrop of the two formations, which 

 does not exactly coincide with the direction of greatest thickness change. 

 The Weno and Pawpaw strata outcrop in a line passing about a mile east 

 of Gainesville, Cooke County, and thence nearly south to near Denton; 

 thereafter the boundary between the two formations runs near Fort Worth, 

 west of Cleburne, Riovista and Blum. 



The outcrop thus from the Red River to the Brazos has a general trend 

 of east of north, while the direction of greatest thickness change is slightly 

 east of north. (See figure 3). 



'Gabb: Pal. Cal., vol. 2, p. 257 ff. 



2 Pelix and Lenk: Beitr. z. Geol. u. Pal. d. Rep. Mex., II, p. 28. 



