Vol. V] BUMBLE— TERTIARY DEPOSITS IM NORTHEASTERN MEXICO 193 



the valley of the river for two miles to the southeast. This 

 is more than 20 miles west of the exposure of any beds we 

 have so far recognized as Oligocene. The Coquina was also 

 seen west of Chorreras, where it apparently rests upon the 

 Fayette and between Abasolo and Soto la Marina in contact 

 with the Cretaceous. In the San Jose de las Rusias region 

 it was also observed in several places forming the tops of 

 the hills. It is probably of Neocene age. 



Reynosa 



The eastern border of the outcrop of the Reynosa lime- 

 stone was traced by Professor Cummins from Reynosa south- 

 ward to the Conchos River in the vicinity of Rinconada. 

 From this border the Reynosa spreads westward covering 

 more or less of the area underlain by the Tertiaries here de- 

 scribed, and in places extends to the foot of the Sierra Madre. 

 One of the best exposures seen was at Abasolo in the Soto la 

 Marina River, where the Reynosa (overlying 60 feet of blue 

 Papagallos shale) shows 40 feet of a conglomerate of blue 

 limestone pebbles overlain by 60 feet of tuffaceous limestone. 

 Many good sections of it were secured from the logs of water 

 wells in the area. At several places small basins were found 

 in it, in which deposits of Equus bed material and fossils 

 occur as they do around San Diego, in Duval County, Texas. 



