THE WEST POINT, TEXAS, SALT DOME 653 



There is a gap, through which it is possible that the drainage 

 once left this dome, about one-fourth of a mile south of the West 

 Point Mountain gap. 



The broadening of this valley into the crescent-shaped area 

 already mentioned and the formation of Blue Lake and the imper- 

 fect drainage systems leading from it are evidently due to the 

 drainage channels working down the dip toward the point of outlet 

 and the fact that they have apparently reached the base-level of 

 the Trinity River. 



This ring-shaped valley, both in its narrow and broader courses, 

 is a barren, open, prairie-like area covered with a sort of coarse 

 marsh grass and is quite conspicuous because of its peculiar form 

 and because of the vistas which it affords in this more or less 

 wooded region. 



Throughout the, entire course of the valley, though occurring 

 for the most part on its outer edge, are numerous springs and boggy 

 places formed by the seeping of water. These springs are mostly 

 of fresh water except for the salts leached from the formations 

 from which they rise and which often forms incrustations of salt 

 around the springs. 



These springs are evidently formed by artesian water collected 

 by the normally southeastward-dipping sands of the Wilcox forma- 

 tion over the large areas where it outcrops to the westward and 

 coming to the surface here where the Wilcox is turned sharply 

 upward around the edge of the salt core of the dome. The rarer 

 brine and sulphurous water springs, some of which are found just 

 south of West Point Mountain, doubtless rise from greater depths 

 through faulting around the perimeter of the salt core. 



Some of the brine springs near West Point have been worked 

 intermittently for salt since before the Civil War. 



These artesian springs bring up fine-grained sand and clay and 

 thus form mounds, some examples of which are several feet across. 

 Woodruff' cites the mounds formed along this ring-shaped valley, 

 particularly on its north side, as excellent examples of the small 

 mounds which are so typical of coastal-plain topography. 



The outer circle of hills is generally higher than the inner mound 

 and the hilly area extends off to the south and west in the dissected 



' E. G. Woodruff, op. ell. 



