40 University of Texas Bulletin 



DENTON: 



Top of Gryphea washitaensis conglomerate, in bed of creek 2.0 



Further sections of the Weno formation in Denton, Johnson, and other counties have 

 just been given in the discussion of the Pawpaw formation (q. v.). 



STRATIGRAPHIC CORRELATION 



NORTH CENTRAL TEXAS AND SOUTHERN OKLAHOMA 



The Weno and Pawpaw formations can be traced continuously through 

 these two regions and their correlation is obvious. As has been already 

 noted, the sandstone facies of the Pawpaw formation has been included by 

 Taff in his Bokchito formation. This facies is similar at Gainesville, Den- 

 ison and Bokchito, and in itself affords insufficient differences to be con- 

 sidered as a different formation on the two sides of the Red River. The 

 whole Weno formation is also included in the Bokchito formation of Taff. 

 Taff's tabulation of equivalencies 1 makes clear that the Bokchito forma- 

 tion is to be considered equivalent to the undefined upper part of the 

 Georgetown limestone in the Austin quadrangle, but to what formations 

 in North Texas is not clear. However, his Caddo formation is described 

 as having at its top a bed of oyster shells "similar to those occurring below 

 and at the top of the Kiamichi formation" (ibid, p. 6). This is the Den- 

 ton marl and has characteristic Denton fossils, and therefore the base of 

 the Bokchito formation is to be considered as the base of the Weno. 2 



SOUTH CENTRAL TEXAS 



The Weno and Pawpaw formations have been traced with certainty to 

 the Brazos River south of Blum. The regional and facies differences in 

 Central Texas make correlation difficult on account of the smallness of the 

 known Del Rio fauna. It is presumed that the Exogyra arietina zone of 

 the basal Del Rio clay is continuous with that of the Mainstreet limestone 

 north of the Brazos near Blum, and that the Nodosaria texana zone present 

 in West Texas at the top of the Del Rio just beneath the Buda limestone 1 

 but reduced or absent in Central Texas does not correspond to the promi- 

 nent Nodosaria zone found at the top of the Weno and the base of the Paw- 



!Taff : Atoka Folio, p. 6. 



2 Stephenson (U. S. G. S., Prof. Paper 120-H, pi. XVIII) places the Denton clay 

 member and the Ostrea carinata bed capping it at the base of Taff's Bokchito forma- 

 tion; and also, very curiously, puts the "Gervilliopsis bed" near the base of the 

 Denton clay. 



3 B6se: Univ. Texas Bull. 1902, p. 19. 



