THE WEST POINT, TEXAS, SALT DOME 66 1 



This very peculiar type of structure is common in the Rou- 

 manian salt domes, where it has been studied by Mrazec/ who 

 has designated the salt-dome structure with intruded and faulted 

 core — his noyau de percement or core piercement structure — as 

 "diaper" structure. Deussen^ describes this very type of "pierce- 

 ment" structure in the Humble field where he regards the "Black 

 Shale" Yegua as having been punched upward through the over- 

 lying Catahoula-Fayette sandstone series. 



It is the writer's opinion that these domes were formed during 

 very late time. The youngest formations outcropping near the 

 domes have been involved in the deformation resulting from 

 the intrusion or formation of the salt plug in every instance. The 

 extreme youth of most known salt domes is, to the writer, a most 

 significant fact. Sediments of Quaternary, perhaps of recent age, 

 have been involved in the formation of the salt domes of coastal 

 Texas and Louisiana. Pleistocene sediments were markedly folded 

 by the formation of the Mexican salt domes. The mother-forma- 

 tion from which the salt of the Roumanian and Transylvanian 

 domes is supposed to have been derived is of Miocene age and many 

 of the German salt domes pierce Tertiary strata. 



All of this points to the extreme youth of salt domes. It is 

 doubtful whether a salt dome whose formation can be established 

 beyond doubt as having occurred in pre-Tertiary time can be 

 cited. This suggests that salt domes are, as the geologic time- 

 scale goes, only transient affairs, and consequently theories of origin 

 implying long life or great age for a dome should be looked upon 

 with suspicion. 



OIL AND GAS POSSIBILITIES 



The West Point salt dome is believed to be a structure of type 

 suitable for the accumulation of oil and gas deposits in commercial 

 quantities. The upthrust here is not so great as at the Palestine 

 and Keechi domes and it seems probable that the sedimentary 

 formations are less faulted and broken than at those domes. This 

 condition favors the West Point dome. 



' L. Mrazec, "Les Plis a noyaux de percement," Bull. Soc. Sci. Bucaresl, 1906: 

 Monit. due Petrole Roumain, X (1908), 915-16. 

 ^ Alexander Deussen, op. cit. 



