372 GEOLOGY OF NORTHWESTERN TEXAS. 



e. Salt Fork of Brazos, near mouth of Salt Croton Creek. 



f. Salt Croton Creek. 



g. Dove Creek. m 

 h. Salt Croton Creek. 



i. Big Duck Creek. 



j. Red Mud Creek. 



H. Haskell. 



D. Dockum. 



K. Kiowa Peak. 



1. Upper part of the Albany Beds of the Carboniferous. 



1 to 2. Clear Fork Beds of the Permian. 



2 to 3. Double Mountain Beds of the Permian. 

 3". Triassic. 



3 to 4. Triassic. 

 4. Tertiary. 



The local sections going to make up this general section are also given in 

 the general report on the Permian. 



The provisional subdivision of the Carboniferous as given on Plate VII 

 is made up of the several beds as I found them in the Northern and Central 

 areas of the Carboniferous formation in the State, and are as follows, begin- 

 ning at the base: 



1. Bend Division. 



2. Millsap Divison. 



3. Strawn Division. 



4. Canyon Division. 



5. Cisco Division. 



6. Albany Division. 



The following is a brief description of these various divisions: 



Bend Division. — This division is found only in the Central Field, and lies 

 along the edge of the Silurian, dipping away from it in almost every direction. 

 It is composed of hard blue limestones and blue and black shales. This di- 

 vision is very readily distinguished from the overlying sandstones of the 

 Strawn division. It is that part of the strata which was referred by Mr. Tarr 

 in the First Annual Report to the Sub-Carboniferous, and has been already 

 noticed at some length in this Report, so that no further description of the 

 contacts between it and the other strata need be made at this place. 



Millsap Division. — This division is found only in the Northern area, being 

 entirely missing in the Central area. It embraces all the strata in the North- 

 ern area below Coal Seam No. 1. It is mostly composed of blue and black 

 clays, with an occasional sandstone and limestone, and an occasional bed of 

 sandy shale. The limestones are generally very hard and break with sharp 

 edges. This is the material used for macadam on the streets of Dallas. 



The strata of this division are well developed in the vicinity of Millsap, on 



