298 II. T. HlLL CxEOLOGV of REi) E.IVEU. 



Page 



Austin Section 319 



Shoal Creek Limestone 319 



Exogyra arietina Beds 321 



Fort Worth Limestones 323 



Denison Section 324 



Kiamitia Clays 324 



Duck Creek Chalk 325 



Fort Worth Limestones 326 



Denison Beds 327 



General Remarks on the Sections 331 



Western Shoreline of the Washita Division .... 332 



Oscillations of Land and Sea recorded in the Region 333 



Conclusions as to the Cretaceous Section 3*6 



Comprehensive Position of the Region geologically. 



Although Red river is one of the most important of the western rivers, 

 its adjacent territory has not been thoroughly explored or surveyed. In 

 1852 Marcy's expedition reached the river at Preston, near the western 

 border of the region discussed in this paper, and proceeded from thence 

 westward to the headwaters of the stream. Its lower portion, east of 

 the Texas-Louisiana line, has been reported upon by various engineers 

 as to its navigability. The medial portion between these points has not 

 been seriously studied, and little has been written upon the geology of 

 the adjoining country. La Salle, De Soto and other early pioneers 

 crossed this portion of the river previous to the present century. Here 

 Nuttall botanized, and Catlin painted some of his most interesting por- 

 traits of Indian life. 



The only early pioneer geologists who touched the area were Dr G. G. 

 Shumard and Jules Marcou, the latter reaching it at its northwest corner. 

 Their contributions were of that class of fragmentary but important 

 descriptions which cannot be overvalued. 



In the years 1887 and 1888 it was my privilege to make a rather 

 thorough survey of the southwestern portion of Arkansas, and during 

 previous and subsequent years I made frequent reconnaissance into the 

 Choctaw and the Chickasaw Nation^ and the opposite counties of Texas. 

 This portion of our country is of exceeding geologic interest, in that 

 here the peculiar geographic features of the Texan and Cordilleran 

 region make their final disappearance eastward toward the Mississippi 

 river and meet the geologic and geographic features which belong to 



* In this region the term "nation" means the area in Indian Territory occupied by an Indian 

 tribe, and it is so used in this paper. 



