INTRODUCTION. 241 



Other writers upon Texas, before and after Kennedy, have presumed to 

 discuss vaguely the Geology, but they have either put forth erroneous views, 

 or have failed to notice any difference between the rocks of the interior and 

 the adjoining areas. Even as late as 1859, Prof. G-. C. Forshey* seems to 

 have regarded the central area as a continuation of the great Cretaceous 

 basin, although he refers to granite and Paleozoic rocks occurring farther 

 west among "the elevated mounds and conical hills that abound at the 

 sources of the Colorado and the Brazoe." 



Most of the works already quoted contain maps of Texas, upon which the 

 topography of the Central area is depicted upon a small scale with varying 

 degress of accuracy, but none of them give a very correct idea of the 

 geography. 



In 1846 Dr. Ferdinand Rcemer published the first really scientific account 

 of the region bordering upon this district, but his observations at that date 

 extended only to near the edge of the Cretaceous escarpment upon the south. 

 His conclusions regarding the inner area were erroneous, because they were 

 based upon information given by others. Omitting his faulty description of 

 Enchanted Rock, which he had not seen, his generalization is as follows: f 



This fact, in connection with the other one that on the San Saba River silver mines have 

 been worked formerly by the Spaniards in a plutonic rock, seem to lead to the supposition 

 that here on the tributaries of the Colorado we arrive at the boundary where the stratified 

 rocks of the east side of the continent come in contact with the crystalline masses of the 

 Rocky Mountains. If this supposition is correct, it follows that the Cretaceous formation 

 is the only one of the whole series of stratified rocks which exists in this part of Texas. 



In a later paper,]; after announcing his discovery of granite and Paleozoic 

 rocks, he summarizes as follows: 



Surrounded by these Cretaceous deposits, there exists between the Pedernales and San 

 Saba rivers a belt of granitic rocks and of Paleozoic strata. The latter are characterized by 

 their fossils as Silurian strata and Carboniferous limestone; both are different in their organic 

 character from the corresponding formations in the Mississippi valley, as might be expected 

 considering the great distance and difference of latitude. 



On nearly all of the old maps a prominent mountain range was laid down 

 in the San Saba region. Roemer was the first to call attention to the non- 

 existence of such elevations " above the general level of the table land." As 

 a result of his later field studies, which included general geologic sections 

 across the Central area, there appeared in 1852 that great work,§ which, to- 



* Texas Almanac, 1859, p. 133. 



f American Journal of Science (2d ser.), vol. II, 1846, p. 364. 



^Contributions to the Geology of Texas. By Dr. Ferdinand Roemer. American Journal 

 of Science (2d ser.), vol. VI, pp. 28, 29, 1848. 



§Die Kreidebildungen von Texas und Ihre Organische Einschlusse. Bonn, 1852, with 

 plates of fossils. 



