1 6 THE PERMO-CARBONIFEROUS RED BEDS OF 



and thinning were found to be parallel belts lying north and south at right angles 

 to the major drainage-lines. Two of these belts, together with an intervening 

 region about 8 miles across, were studied. The sandstones thicken at the expense 

 of the shales, sometimes eHminating them. In one instance a thin Kmestone was 

 traced southwest into one of these zones. A sandstone 20 feet or more beneath 

 the limestone thickens and rises above the limestone, and practically unites with 

 the sandstone some distance above it. The limestone seems to die out a few feet 

 from the sandstone, but farther west the latter shrinks to its normal thickness, 

 and the limestone is present in its proper position, with its usual characteristics." 



As early as 1897, Cummins noted the same thing, but did not grasp 

 its general character.* 



' ' By walking along the outcrop every foot of the way we were enabled to note 

 the gradual change in the lithological character of the bed. ' ' [Following a prominent 

 bed of the Albany northeastward] "wefound the limestone * * * gradually changed 

 in composition to a calcareous sandy clay, entirely destitute of fossils. * * * 

 North of the Brazos River, in the area heretofore designated as the Wichita division 

 in previous reports, the strata of the escarpment became more and more composed 

 of red clay, and the limestone beds less conspicuous. The limestone gradually 

 loses its limy nature." 



Gordon records the same observations:^ 



"The red sandy shales and red sandstones in the Wichita Valley region were 

 replaced southward in large part by blue shales, light-colored sandstones, and 

 limestones. In some places the transition from a sandstone to a limestone was 

 plainly seen. * * * It is the conclusion of the author that the red beds of this 

 region are the near-shore representatives of the Albany, and the decision as to their 

 age will rest upon that of the latter." 



In 191 1, Gordon,'' discussing the relation of the Albany to the Wichita, 

 says: 



"When traced northward, the limestones of both the 'Albany' and the Cisco 

 formations diminish in thickness, while there is a corresponding increase in the 

 intervening beds of shale. In the case of the 'Albany,' the limestones show also 

 a change, becoming more earthy and irregular in their texture, and some of the beds 

 passing into gray indurated clays. The few limestones in the upper part of the 

 Cisco formation disappear entirely in the northern part of Young County. Along 

 with this change there is an increasing development of red clay, alternating with 

 blue. * * * 



"At Fane Mountain, a low elevation in the southeastern comer of Throck- 

 morton County, is an outcropping of limestone characterized by an abundance of 

 Myalina permiana. These beds occur at intervals northward in eastern Throck- 

 morton County, and at Spring Creek in the northwestern comer of Young County 

 they outcrop in the bank of the river about a mile from the post-office. Here 

 the beds show a local gradation into sandstone, suggesting near-shore conditions 

 of sedimentation. * * * 



" Cummins, The Texas Permian, Trans. Texas Acad. Sci., vol. 11, No. i, p. 95, 1897. 

 i' Gordon, The Red Beds of the Wichita-Brazos Region of North Texas (Abstract), Science, vol. 29, 

 1909, P- 752- 



"Gordon, The Wichita Formation of Northern Texas, Jour. Geol., vol. 19, 191 1, p. 118. 



