History of Concepts of Gulf Coast Salt-Dome Formation

Abstract

This paper reviews the development of ideas of salt-dome formation in the Gulf Coast, leading to the concept of fluid-like flow under gravitational forces due to the salt being lighter than the sediments. The earlier ideas, many now disproved, were presented in considerable detail in the 1926 A.A.P.G. volume, Geology of Salt Dome Oil Fields, particularly in the papers by DeGolyer and Barton. These are reviewed briefly in the present paper as background for later developments. A review of early model experiments to simulate salt-dome formation shows that they were grossly deficient, quantitatively. Later models, using fluid-like materials are in much better accord with the mathematical restrictions on their properties. Those using a combination of fluids and soft materials with a small but definite shear strength, with deformation due to gravitational forces arising from differences in density, and with mechanical properties which are at least roughly correct mathematically, give results which appear to simulate actual dome formation fairly well. The model dome forms and the deformation of the adjacent materials are reasonably consistent with those known from geophysical results and drilling, particularly since the general use of electric logs has shown the common occurrence of rim synclines and faulting over and around the domes.