28 THE PERMO-CARBONIFEROUS RED BEDS OF 



sandstone, approximately equal distances apart in the lower 125 feet seen. The 

 whole succession of beds which it has so far been possible to construct from exposures 

 is, therefore, as below: 



Section of the Wichita beds known from exposures. 



Thickness 

 in feet. 



Shales above the Bluff bone-bed 32 



Bluflf bone-bed 0-5 



Shales between the Bluff bone-bed and the Beaverburk limestone 65 



Beaverburk limestone 0-3 



Shales and sands below the Beaverburk hmestone 125 



222-230 

 "It is possible that some of the beds described in the east half of Wichita 

 County, and in the northwest part of Clay County, are to be correlated with some 

 part of the above general section, but it does not seem that such correlation can 

 be made in the usual way. There seem to be no identifiable horizons in this part 

 of the field, so far as yet determined." 



It is evident from the above description, quoted from Udden, that he 

 believes that a good portion of the Texas Permo-Carboniferous beds were 

 deposited upon or near a sea-shore affected by variable and local currents. 

 Also that he believes that the sea was located to the west, or over the beds 

 discussed, with a land to the east. These ideas are almost diametrically 

 opposed to those held by the author and to those of most, if not all, of the 

 men who have written upon the region. Whichever idea may prevail in 

 the end, it can not detract from the value of the observations made by Udden. 



THE CLEAR FORK FORMATION. 



The limestones which were considered by Cummins as most nearly 

 marking the base of the Clear Fork appear for the first time a little east 

 of the line which separates Baylor and Archer Counties, and extend to beyond 

 the Big Wichita River, in a nearly north-and-south line. On the north they 

 disappear beneath the surface deposits beyond Burk Station, and on the 

 south they may be traced to a contact with the Cisco, near the northwestern 

 corner of Young County. As stated above, Gordon found it impossible to 

 distinguish between the Clear Fork and the Double Mountain beds and 

 includes a large part of what Cummins regarded as Clear Fork in the Wichita. 

 However this may be finally settled, the fact remains that there is a decided 

 difference between the faunae of the beds above and below the limestones 

 (see list, p. 96), and the author of this paper is inclined to use the term 

 "Clear Fork" to indicate the series of beds beginning with the limestones 

 and carrying the upper fauna. Cummins has drawn an approximate line 

 between the Clear Fork and the Double Mountain, which passes south near 

 the line between Wilbarger and Hardeman Counties, just west of Seymour, 

 in Baylor County, and then west of south to or just west of Haskell, in 

 Haskell County. 



Cummins 's original description of the Clear Fork is as follows:" 



' ' The Clear Fork, or Middle Beds of the Permian, are composed first of bedded 

 limestones, magnesian and earthy, which are sometimes carbonaceous enough to be 



" Cummins, First Annual Report, Texas Geological Survey, 1889, p. 188. 



