662 E. DeGOLYER 



The series of rocks forming this structure include known 

 petroHferous or gas-bearing formations as follows: the Navarro 

 formation, Nacatoch sand, is gas-bearing in the Mexia-Groesbeck 

 and Corsicana fields and oil-bearing in the northwestern Louisiana ; 

 the Taylor marl includes the oil-bearing formation at Corsicana; 

 the Austin chalk is oil-bearing in the small fields near San 

 Antonio; the Eagleford contains the gas-bearing Blossom sand 

 member of northwestern Louisiana; and the Woodbine sands 

 include oil-bearing formations in northwestern Louisiana. 



A test well 3,500 feet deep on the upper part of the flank of the 

 West Point dome should pass through this entire section of rocks. 



The direct indications of the existence of oil or gas deposits in 

 this dome consist of the gas and oil shows reported in various wells 

 drilled around this dome, as already stated, and gas seeps and 

 sulphurous water springs near West Point Mountain which have 

 been reported by Chapman and Hager. No search for direct 

 indications was made by the writer, and he is therefore unable to 

 confirm their existence. 



N^one of the salt domes of Texas or Louisiana have yielded gas 

 deposits of marked commercial importance, though many of them 

 have been the source of exceedingly rich oil deposits. None of the 

 interior domes have yet yielded commercial oil production. Some 

 heavy oil (8° Be.) was found in the Woodbine sands on the flank 

 of the Keechi dome in the Texas Company's well No. i Barret and 

 Greenwood. 



Petroleum in commercial quantities in salt-dome structures of 

 the Gulf coastal plain has as yet been found to occur only under 

 one of the four following conditions: first, in the cavernous lime- 

 stone and gypsum cap immediately overlying the top of the salt 

 mass, the so-called "cap rock"; secondly, in sands pierced by the 

 salt, abutting against and sealed by the salt, and dipping away 

 from it, the so-called "lateral sands" or "deep sands"; thirdly, in 

 sands or sandstones for the most part lenticular and occurring above 

 the cap rock or the salt dome itself, the so-called "shallow sands" 

 in the Humble, Batson, Spindletop, and other fields or the deep 

 sands in the so-called "deeply buried domes" such as Goose Creek 



