TARIS SECTION. 307 



The Fort Worth, Duck creek and Main street limestones of the 

 Washita division being softer than the Goodland, their interior-facing 

 escarpments of stratification are less pronounced, but nevertheless trace- 

 able throughout their extent until these formations are lost in the fault- 

 ing south of the Brazos. The Austin chalk forms an escarpment of 

 stratification even higher, but less angular than the Goodland limestone. 

 It does not outcrop eastward down the valley of Red river as do the 

 others. 



PAEIS SECTION. 



One hundred miles east of Denison a parallel section will show dif- 

 ferentiation from the features of the Preston section. The Trinity val- 

 ley, the Goodland limestone and the Washita dip plains are seen in the 

 Choctaw nation as in the Chickasaw. The Dakota (Cross Timber) hills 

 have disappeared, however, and this formation occupies the lowest bluff 

 of the low river valley. The Preston and the Cook springs fault have 

 passed southeastward off our map and do not appear along this line. 

 The Lower Cretaceous no longer outcrops south of Red river, and the 

 Austin chalk has disappeared entirely by faulting, while the latter beds 

 of the Upper Cretaceous or Glauconitic division, unrepresented in the 

 Denison profile, appear in the southern portions of Fannin, Lamar and 

 Red River counties. They, with the Eagle Ford, constitute fertile black 

 prairips* exceedingly difficult to differentiate from one another, but never- 

 theless distinguishable, the latter occurring mostly north of the trans- 

 continental branch of the Texas Pacific railroad running from Texarkana 

 through Sherman to Whitesboro'. The structural dip plains, so con- 

 spicuous in northern Grayson county, no longer occur on the Texas side 

 of Red river, and are limited to the narrowing Lower Cretaceous prairies 

 near Goodland,t while on the Texas side the contour is a low arc form- 

 ing the divide of the Red and the Sulphur river. 



Here the fluviatile deposits have increased in width to many miles 

 along Red river, which here fiows through Dakota. From Arthurs bluff 

 I have made three collections of the Dakota flora, which are now in 

 Colum])ia college, the National Museum and in the state capitol of 



Texas. 



The members of the Glauconitic division in this section throw great 

 light on the Upper Cretaceous history, showing that the beds I have 



*The topography of the black prairies of Texas and their extent are mapped and described in 

 my report On the Occurrence of Underground Waters etc , 52d Cong., 1st sess., Sen. Doc. 41, Wash- 

 ington, 18'.i3, 2d edition. 



tThe Goodland prairies on this profile are tlie original plains of the Kiamishi, from which 

 Dr Pitcher collected the famous Gryphcea pitcheri of Morton in 1827, the first to be described of 

 what are now known to be Comanche fossils, and which has been almost inextricably confused 

 with others, the true characters and specific definition of which I shall soon present in another 

 paper, 



