THE LOWER OR COMANCHE SERIES. 



133 



The Lower or Coma/ache Series (Colorado River Section.) 



DIVISIONS. 



BEDS. 



HORIZONS. 



TYPICAL OCCURRENCE. 



3. Upper or 

 Washita Divis- 

 ion. 



Shoal Creek Limestone (at 

 Austin). 



(Impure.) 



In North Texas replaced by 

 Denison or 0. Quadriplica- 

 ta beds. 



Shoal Creek, Austin. 



S. bank of Colorado, 

 at fish ponds. 





Exogyra arietina clays. 



Final G. pitcher -i, var. navia 

 E. arietina. 



Shoal Creek at Twenty- 

 fourth Street. 

 Bluff near Barton Springs. 





"Washita or Fort Worth Lime- 

 stone (chalky). 



Terebratula Wacoensis. 



3d Grypheea beds. G. Wash- 



itaensis, with 0. Carinata, 



0. Sinuata, Macraster ele- 



gans. 



Fort Worth, Texas; rail- 

 road cut, W. Austin, 3a- 

 lado, etc. 





Upper Caprotina Limestone. 



Final Caprotina horizon. 



S. base of Bonnel; Mc- 





Limestone Flags. 



Donald's brickyard, 

 Austin. 



2. Middle or 

 Fredericksburg 

 Division. 



Caprina chalky Limestone 

 with flints. (Persistent.) 



Sehloenbachia aeuto-carinatus. 

 {A. peruvianus, de Buch, 

 Marcou.) Rudistes, Mono- 

 pleura, Caprotina, etc. 



Summit of Jollyville and 

 Jehosaphat Plateaus, 

 and bluffs of Deep Ed- 

 dy, Austin. 





Comanche Peak chalk beds. 

 (Persistent.) 



Comanche Peak Fauna, 

 Ammonites pedernalis, Tox- 

 aster texanus. 



G. pitcheri beds, with E. tex- 

 ana. Culmination bed of 



Comanche Peak, etc. 



Summit of Mount Bar- 

 ker, and many other 

 localities. 







to 



m 



_fl 



"o 



'a 

 o 



Bench of Mount Barker. 





Lower or al- 

 ternately ar- 

 enaceous, 

 m a g n e s ian 

 calcareous 

 division. 



Sub- Divisions. 



E. texana. 

 Tylostoma pedernalis. 



Celestite beds. 

 Nerinea Austinensis. 



Tinoporous chalk. 



Summit of Mount Bonnel 

 above celestite beds. 





Upper beds of 

 thin oolitic 

 strata. 







Bases of Mounts Barker 

 and Bonnel, north of 

 fault. 





Middle beds, 

 with thick 

 m a gnesian 

 strata. 



Base of Bonnel ridge, 

 near Bull Creek. 





Basal arena- 

 ceous beds, 

 with thin 

 strata. 



Nerinea acus. 

 1st Caprotina horizon. 



Travis Peak P. 0. 



1. iLower or 

 Trinity Divis- 

 ion. 



Upper or Packsand Beds. 



(Locally variable.) 



Basal or Contact Beds. 



(Locally variable.) 





Sycamore Creek, Burnet 

 County; Travis Peak P. 

 0., Travis County. 



Pre-Cretaceous. 









