(From report prepared by L. S. Melzer and G. C. Clark)

In the East Texas district, 27 salt domes have been definitely identified. Of this number, 10 are classed as deep-seated and 17 as piercement. Two of the piercement domes, Boggy Creek and Kittrell, are found to be productive from the Woodbine and the lower Claiborne respectively. Seven deep-seated domes are found to be productive from formations varying in age from Comanche to Nacatoch. All domes, both deep-seated and piercement, are reflected as gravity minima, with the exception of Marquez and Kittrell which are shown by gravity surveys as maxima.

All piercement domes in the East Texas district grew from the deepest part of local synclines and all are situated within the regional province known as the Tyler basin. The Upper Cretaceous

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beds are found to thicken and dip steeply away from the salt core, indicating structural movement both during and after deposition. Thinning of Upper Cretaceous sediments over the deeper-seated domes where the evidence has not been obliterated confirms this structural growth. The basin position of these domes and the time of origin indicates that the Lower Cretaceous sediments dip toward the domes.

Deep-seated domes are found to have many of the aspects of anticlinal structures. These domes began their growth much earlier than piercement domes and are located, and have always been located, on locally high areas. Thinning of Lower Cretaceous sediments furnishes evidence for their early origin, and uniform thinning of Upper Cretaceous beds suggests that these domes grew uniformly throughout Upper Cretaceous and Tertiary time and were never subjected to the violent displacements which affected their neighbors, the piercement domes. These structures are ideal reservoir anomalies and seven out of ten are now producing, with the possibility that some of the others will produce with subsequent development.

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