130 II. F. BAIN — GEOLOGY OF THE WICHITA MOUNTAINS 



ion that there has been recent volcanic activity in the region. The 

 greenstone dikes are certainly the most recent igneous rocks. The tuffs 

 and rhyolites found are pre-Cambrian, and the resemblance of certain 

 of the mountains to "an ancient crater" is fanciful only. It has been 

 impossible to recognize all the peaks named by this party and to per- 

 petuate these names. Wherever the recognition seemed secure the names 

 have been used. Mount Webster, located and ascended by Marcy's 

 party, seems now unknown. From the general references to its position 

 and the sketch given of its outline it seems probable that it is the peak 

 now known as Baker, but in the absence of accurate maps there will for 

 some time be confusion regarding the geograph} T of the area between 

 Saddle mountain and the Mesquite valley. 



The maps of the region are quite imperfect. The land survey seems 

 to have been more than usually inexact. The sketch map (figure 1) 

 given with this paper is from a blue print of a map made by the railway 

 engineers. The position of the various mountains is set down from 

 checked compass readings, where other data are lacking. 



Physiography 



The Wichitas rise abruptly from the great prairie plain about midway 

 between the Washita and Red rivers. Cache creek flows through the low, 

 circling hills of the east end, and on the west the North fork of Red river 

 separates the Wichitas from the Navajo mountains which lie in Greer 

 county, Oklahoma. 



The core of the mountains is a rugged mass of igneous rocks. On the 

 north side, circling around the east as far west as the south side of Signal 

 mountain, is a lower range of limestone hills of less rugged aspect and 

 with rounded slopes. These hills rise 70 to 400 feet above the plain and 

 are in part detached, such as Rainy mountain and the elevation near it, 

 and in part massed together. These limestone hills are separated on 

 the north from the main mountains by a wide valley, down which for 

 much of the way Medicine Bluff creek flows. This stream, which by 

 Marcy's party was evidently mistaken for the main branch of Cache 

 creek, cuts through the porphyry of Carroll ton mountains, forming a sharp 

 bluff 250 to 300 feet high, from which the stream takes its name and 

 which is regarded with a certain amount of awe by the Indians. 



The mountains themselves consist of a series of detached and semi- 

 detached mountains, and are crossed by wide passes which are nearly 

 as level as the surrounding plain. Between the mountains flat grassy 

 plains are found and spurs protrude through the plain at some distance 

 from the main mountain mass. The exceedingly rugged topography of 



