Abstract The Spindletop oil field was the first and one of the most brilliant of the Gulf Coast oil fields. Spindletop is a characteristic Gulf Coast salt dome and is composed of a steep-sided, relatively flat-topped, circular salt core with a diameter of about 1 mile, and with a limestone, anhydrite, gypsum cap surmounting the salt. Most of the oil was produced from the porous cavernous limestone at the top of the cap. The early gushers have never been equaled in the United States for the size of their daily flush production. Few fields in the United States of like size, 265 acres, have had as big a production, thirty million barrels in the first three years, and a total of over fifty million barrels to date.

Abstract A core of rock salt containing potassium salts and fossil algae was recently taken, at a depth of 4,800 feet, from Gray No. 1 well of the Rycade Oil Corporation at the Markham, Texas, salt dome. This is the first occurrence of potassium salts reported from the salt domes of the United States, and is probably the most important contribution of fact to a study of their origin for a score of years. The first appreciable step toward a knowledge of the real structure of the domes was the discovery of the main salt mass of Petite Anse, one of the Five Islands of Louisiana, by the deepening of an old brine well in 1862. We came to know the general form, composition, and structure of our domes as a result of the vigorous drilling campaign which followed close upon the discovery of an oil pool on the Spindletop dome in 1901. The active exploration of the domes since that time, in the mining of oil, sulphur, and salt, has served chiefly to emphasize the essential regularity of the domes, their general conformability to type, and to emphasize the uplift of the overlying and contiguous strata by the formation of the salt core and cap rock of the dome. The first theories of origin—little more than vague speculations based on entirely inadequate conceptions of the true nature of the domes—regarded them as old Cretaceous outliers in Tertiary seas. With a fairly satisfactory working knowledge of the true constitution of the

Abstract Salt is a crystalline aggregate of the mineral halite, which forms in restricted environments where the hydrodynamic balance is dominated by evaporation. The term is used non-descriptively to incorporate all evaporitic deposits that are mobile in the subsurface. It is the mobility of salt that makes it such an interesting and complex material to study. As a rock, salt is almost unique in that it can deform rapidly under geological conditions, reacting on slopes ≤0.5° dip and behaving much like a viscous fluid. Salt has a negligible yield strength and so is easy to deform, principally by differential sedimentary or tectonic loading. Significant differences in rheology and behavioural characteristics exist between the individual evaporitic deposits. Wet salt deforms largely by diffusion creep, especially under low strain rates and when differential stresses are low. Basins that contain salt therefore evolve and deform more complexly than basins where salt is absent. The addition of halokinetic processes to the geodynamic history of a basin can lead to a plethora of architectures and geometries. The rich variety of resultant morphologies have considerable economic as well as academic interest. Historically, salt has played an important role in petroleum exploration since the Spindletop Dome discovery in Beaumont, Texas in 1906. Today, much of the prime interest in salt tectonics still derives from the petroleum industry because many of the world's largest hydrocarbon provinces reside in salt-related sedimentary basins (e.g. Gulf of Mexico, North Sea, Campos Basin, Lower Congo Basin, Santos Basin and Zagros). An understanding of