Weno and Pawpaw Formations 35 



more southward section is found. However, in, West Texas, on passing 

 northward into the near-shore facies (as at Kent and Cerro de Muleros) 

 the Weno and Pawpaw formations again thicken, as in passing from Austin 

 to Fort Worth, and show characteristic and so far as can be judged from 

 published accounts .similar fossils. This level at Muleros has echinoids and 

 ammonites and other distinctive fossils (see page 41), but so far the large 

 pyrite fauna of the North Texas Pawpaw has not been reported from West 

 Texas. 



WENO FORMATION 



A summary of the marine facies of the Weno formation and several ge- 

 ological sections have already been given. The Weno formation is compos- 

 ite, and represents different phases of marine deposition both at different 

 places and in its different levels at the same place. In the Red River region 

 the formation is mostly a series of blue shales with clay-ironstone, lime- 

 tone and irregular consolidated sand seams. The ironstone and shale lay- 

 ers are rich in nacreous fossils. The shale is here capped by the Quarry 

 limestone group, which loses its massive character south of Denton County, 

 Passing southward from the Red River, the basal Weno transforms from a 

 clay into a calcareous marl with shelly, often slabby, limestone seams and 

 the upper part after passing rapidly through a marl stage becomes pre- 

 vailingly a soft chalky fossiliferous limestone. This is the situation in Den- 

 ton and Tarrant Counties. The basal division is also capped by a thin 

 chalky limestone which forms a bench, and the Weno thus consists of two 

 terraces, a persistent topographic feature which passes southwards across 

 Denton, Tarrant, Johnson and Hill Counties and disappears only in north- 

 western McLennan County where the Weno limestone consolidates with 

 the Mainstreet and Fort Worth limestones (by the virtual disappearance of 

 the intervening softer formations) to form the middle Georgetown lime- 

 stone. 



In the Red River region the shale (clay) facies predominates from south- 

 ern Cooke County to east of Bennington, Oklahoma. It is conspicuous in the 

 first deep cut of the St. Louis and San Francisco Railway track north of 

 Denison, of which a photograph is given by Stephenson, 1 and in the pit of 

 the brickyard 1% miles southeast of Gainesville ,of which a section is here 

 given. 



'Stephenson, U. S. G. S., Prof. Paper 120-H, pi. XXII B. 



