THE WEST POINT, TEXAS, SALT DOME 655 



except an imperfect outcrop of a heavy yellow sandstone in the 

 road some 1,500 feet due north of the Gin. This sandstone 

 apparently pertains to the Wilcox, and it is beHeved that the central 

 part of the dome is underlain by the Wilcox formation except in 

 the area mentioned as probable Midway and Cretaceous outcrop. 

 Chapman notes that an inlier of the Mount Selman beds is to be 

 found in the central part of the dome, but this was not seen by 

 the writer and, if present, is believed not to be in place. 



All of the outcrops along the circular drainage valley which 

 outlines the dome are of soft white, gray, and yellow sandstones and 

 white, purple, and yellow shales of the Wilcox formation. Most 

 of the dip and strike observations recorded were taken on bands 

 of ironstone concretions in sandstones of this formation. The 

 Wilcox formation also forms all of the lower hills and the base of 

 the higher hills which form the outer edge of the circular drainage 

 valley. 



The upper part of the higher hills around the outer edge of the 

 circular valley are composed of the characteristic ferruginous sand- 

 stones and conglomerates, in places iron ore, of the lower part of 

 the Mount Selman beds, Claiborne, Eocene. The country rock for 

 some miles to the west of this salt dome is of this same formation, 

 though it apparently only caps the hills on the northeast. Hopkins^ 

 describes a section of the Wilcox in a bluff on the bank of the Trinity 

 River at the mouth of Town Creek, some three miles northeast 

 of the dome. 



The dome lies at the easternmost point of a triangular-shaped 

 outlier of Mount Selman beds. Another large irregular outlier of 

 the same formation occurs in northeastern Freestone County. 

 These outliers are cut off from the main body of Cook Mountain — 

 Mount Selman formation, which lies to the eastward in Anderson 

 County, by the broad valley of the Trinity River. 



UNDERGROUND GEOLOGY 



Some five wells, all comparatively shallow, have been drilled 

 on or around the dome, but available information concerning them 

 is scant and inexact; consequently we can do little but speculate 



^ Oliver B. Hopkins, op. cit. 



