12 THE PERMO-CARBONIFEROUS RED BEDS OF 



ance and constitute a marked feature of the formation in Archer and eastern 

 Baylor Counties. The red sediments increase in amount northward until, in northern 

 Throckmorton County and beyond, the red color dominates in the formation. 



"Throughout the northern area the clays are red or red mottled with bluish- 

 white and drab colors. The red clays contain an abundance of nodular concretions 

 of irregular shape, ranging from those the size of a pea to masses 4 or 5 inches in 

 diameter. Many are elongated or subspherical, and some are flattened and stand 

 vertically in the clay, suggesting their origin from the filling of fissures. They 

 consist of clay, iron, and lime, and some of them are either hollow or have their 

 interiors filled with calcareous clay. Here and there is a bed that consists of rounded 

 lumps of hardened clay cemented together by ferruginous matter, which Cummins 

 called a 'peculiar conglomerate.' It is suggested that this deposit may have 

 had its origin in the breaking up of a thin bed of clay soon after deposition, by the 

 action of running water or waves." 



It will be noted that both Cummins and Gordon insist on the absence 

 of any limestone in the lower beds, and, though Gordon has shown that the 

 limestone of Baylor Coimty can be traced southward into the upper "Albany," 

 the author is inclined to believe that the limestone appearing in the eastern 

 part of Baylor County, called Beaverburk limestone by Udden,^ marks so 

 definite a change in conditions that it should be considered as the first 

 member of a separate formation, and the author believes that Gordon's 

 map (fig. I, p. 9) places the western edge of the Wichita too far to the west 

 and that the line drawn by Cummins is more nearly acctirate. 



Transition of Limestones Into Red Beds. 



On the east the Wichita beds shade through red shales and red limestones 

 into pure limestones. This fact has been only slowly accepted, but now 

 seems proven beyond doubt. The following pages contain the accounts of 

 this phenomenon collected from the various authors. 



Adams'' was the first to call attention to the importance of this change 

 and reported his observations in several papers: 



"In tracing the outcrops of the limestone formations of the Carboniferous of 

 Kansas, the writer observed that in going southward there is a gradual transition 

 in the character of the sediments to those which are more arenaceous, and that 

 there is a thickening of the shales and sandstones and a thinning and final dis- 

 appearance of some of the limestones." 



Adams then gives full details of his tracing of the Fort Scott and Elk 

 Falls limestones from Kansas into Oklahoma, where the same series becomes 

 arenaceous and red. 



"From what is known of the Permian limestones of Kansas, they will be found, 

 when followed southward, to diminish in thickness, and this change will be accom- 

 panied by a transition to more sandy beds. 'The Wellington Shales' are probably 

 represented southwestward by formations which are red. The approximate limit 

 of the red color is a line diagonal to the strike of the formations, and is found to 



" Udden, Bull. University of Texas No. 246, 1912, p. 31. 

 '' Adams, Amer. Jour. Sci., vol. xii, igoi, p. 383. 



