66o , E. DeGOLYER 



The West Point dome is a geologic phenomenon so similar to 

 the other interior domes, particularly the nearby Palestine and 

 Keechi domes, that it is undoubtedly of similar origin and probably 

 contemporaneous in formation with them. Deussen' argues that 

 these domes ''were clearly formed in late Cretaceous or early 

 Tertiary time, as is evidenced very clearly in the case of the Keechi 

 dome of Anderson County, where the Wilcox beds of the Eocene 

 rest unconformably on the Navarro beds of upper Cretaceous, the 

 Midway being absent." He further states that the high angle of 

 dip of the Wilcox around these domes, in conjunction with the 

 unconformity, is plain evidence that the growth of the salt core is 

 the result of different movements at different times. 



Hopkins^ accepts, for the Palestine and Keechi domes, Deus- 

 sen's theory of the initial uplift of the dome during- pre-Midway 

 time and the existence of the domes as islands in the Midway 

 sea. This theory is of course proposed to explain the apparent 

 absence of the Midway formations at both the Palestine and 

 Keechi domes. 



This theory is not tenable for the West Point dome, if, as has 

 been suggested, part of the greenish-yellow shales which outcrop 

 west of the Llewellyn Gin are of Midway age. Neither is the 

 theory the only available one, nor, in the writer's opinion, the 

 most satisfactory one, to account for the apparent absence of 

 Midway outcrops at the other domes. 



The country rock is very poorly exposed at the Keechi dome 

 and not much better exposed in the Palestine dome. It is entirely 

 possible that a formation composed chiefly of shale and only a few 

 hundred feet thick, as is the Midway, and occurring in a structure 

 where the rocks are dipping very steeply, may not be well exposed 

 or may have been overlooked. 



If the Midway is absent in the Keechi and Palestine domes, 

 however, the writer would suggest that it may have been faulted 

 out of the outcropping section by having an older formation, say 

 the Navarro, punched through it from below, and into contact with 

 a still younger formation, say the Wilcox, by the upthrust of the 

 salt core. 



' Alexander Deussen, op. cit. ^ Oliver B. Hopkins, op. cit. 



