Texas Salt Domes: Natural Resources, Storage Caverns, and Extraction Technology

This report reviews natural resources associated with salt domes in Texas. Salt domes provide a broad spectrum of the nation's industrial needs including fuel, minerals, chemical feedstock, and efficient storage space. This report focuses on the development, technology, uses, and problems associated with solution-mined caverns in salt domes. One proposed new use for salt domes is the permanent isolation of toxic chemical waste in solution-mined caverns. As the Texas Department of Water Resources (TDWR) is the State authority responsible for issuing permits for waste disposal in Texas, TDWR funded this report to judge better the technical merits of toxic waste disposal in domes and to gain a review of the state of the art of applicable technology. Salt domes are among the most interesting and intensively studied structural-stratigraphic geologic features. Individual domes may be the largest autochthonous structures on earth. Yet many aspects of salt-dome genesis and evolution, geometry, internal structure, and stratigraphy are problematic. Details of both external and internal geometry of salt stocks and their cap rocks are vague, and information is restricted to the shallow parts of the structure. These facts are all the more surprising considering that salt diapirs dominate the fabric of the Gulf Coastal Province, which is one of the most explored and best known geologic regions on earth. This report includes information on present and past uses of Texas salt domes, their production histories, and extractive technologies (see also Halbouty, 1979; Hawkins and Jirik, 1966; and Jirik and Weaver, 1976). Natural resources associated with salt domes are dominated by petroleum that is trapped in cap rocks and in strata flanking and overlying salt structures. Sulfur occurs in the cap rock of many domes. Some cap rocks also host potentially valuable Mississippi Valley-type sulfide and silver deposits. Salt is produced both by underground mining of rock salt and by solution brining. The caverns created in salt by solution mining also represent a natural resource. The relative stability, economics, location, and size of these caverns make them valuable storage vessels for various petroleum products and chemical feedstocks.Bureau of Economic Geolog

Evaluating the Potential of East Texas Interior Salt Domes for Isolation of Nuclear Wastes

At least as early as 1960, the U.S. Atomic Energy Commission was contracting studies of the suitability of salt (halite) as repositories for waste nuclear products. Underground disposal offers the most favorable means of ensuring confinement of a growing volume of nuclear waste products. The chemical and physical properties of salt, either in domes or in bedded layers, have focused principal attention on the potential nature of salt repositories. Bedded salt deposits of various ages occur as strata within numerous sedimentary basins in the United States. In Texas, parts of the Permian Basin, the Palo Duro and Dalhart basins, are currently under investigation to determine waste isolation potential by the Bureau of Economic Geology, The University of Texas at Austin. Texas also contains at least 78 on-land salt domes that are sufficiently shallow to identify by conventional geophysical and drilling/subsurface mapping methods. Of these 78 domes, 20 domes occur within the interior East Texas Basin. Previous workers have considered coastal domes to be unstable and have also rejected about two-thirds of the Texas interior domes for various reasons (to be discussed later). Consequently, using a variety of criteria and data, approximately a half dozen interior Texas salt domes are currently "unrejected" by studies to date. At this time, it is necessary to reassess the earlier studies of East Texas interior domes, review the potential of the domes for nuclear waste isolation, and undertake intensive analysis of selected, high-priority candidate domes. This thorough evaluation must precede any decision concerning the actual use of the domes for nuclear waste disposal. Every conceivable natural factor must be considered and tested if necessary. Principal research effort should be focused very quickly on specific domes. We believe, however, that along with site-specific studies, continuing analysis of regional geohydrologic systems and salt-basin tectonics should be integrated with site-specific evaluations.Bureau of Economic Geolog

Прогноз контурів соляних штоків за даними розподілу товщин відкладів нижньої юри та байоського ярусу середньої юри у південно-східній частині Дніпровсько-Донецької западини

Розглянуто можливість прогнозування контурів соляних штоків за результатами аналізу розподілу товщин окремих стратиграфічних та літологічних комплексів, що перекривають соляні штоки і приштоковые зони. Встановлена закономірність розподілу товщин дозволяє прогнозувати положення кордону соляних штоків у південно-східній частині Дніпровсько-Донецької западини.The possibility of prognosis of contours of salt domes on results the analysis of distributing of thicknesses of separate stratigraphic and lithologic level of blocking salt domes and near-domes zones is considered. The set conformity to the law of distributing of thicknesses allows to forecast position of border of salt domes in south-east part of the Dniepr-Donetsk depression

Attenuation of acoustic waves in glacial ice and salt domes

Two classes of natural solid media (glacial ice and salt domes) are under consideration as media in which to deploy instruments for detection of neutrinos with energy >1e18 eV. Though insensitive to 1e11 to 1e16 eV neutrinos for which observatories (e.g., AMANDA and IceCube) that utilize optical Cherenkov radiation detectors are designed, radio and acoustic methods are suited for searches for the very low fluxes of neutrinos with energies >1017 eV. This is because, due to the very long attenuation lengths of radio and acoustic waves in ice and salt, detection modules can be spaced very far apart. In this paper, I calculate the absorption and scattering coefficients as a function of frequency and grain size for acoustic waves in glacial ice and salt domes and show that experimental measurements on laboratory samples and in glacial ice and salt domes are consistent with theory. For South Pole ice with grain size 0.2 cm at -51 degrees C, scattering lengths are calculated to be 2000 km and 25 km at 10 kHz and 30 kHz, respectively, and the absorption length is calculated to be 9 km at frequencies above 100 Hz. For NaCl (rock salt) with grain size 0.75 cm, scattering lengths are calculated to be 120 km and 1.4 km at 10 kHz and 30 kHz, and absorption lengths are calculated to be 30,000 km and 3300 km at 10 kHz and 30 kHz. Existing measurements are consistent with theory. For ice, absorption is the limiting factor; for salt, scattering is the limiting factor.Comment: 16 pages, 7 figures, submitted to Journal of Geophysical Research - Solid Eart

Salt domes of the United Arab Emirates: evidence for late Neoproterozoic sedimentation and rift volcanism in the northern Arabian-Nubian Shield

Seven of the nine emergent salt domes of the UAE have been examined. They outcrop on the Arabian Gulf islands of Delma, Sir Bani Yas, Arzana, Qarnain, Zirku and Sir Bu N’Air, with one on-land salt dome at Jebal Dhanna. The salt domes range from about 1 km across (incomplete remnant of Qarnain) to over 6 km diameter (Delma) and form dissected hilly topography rising to about 140 m above sea-level (Zirku). The majority of the salt domes are single intrusions but two, Delma and Jebal Dhanna, appear to have multiple phases. The diapirs were emplaced penecontemporaneously with the Miocene country rocks, while evidence of recent localised halokinetic reactivation in small dome-like “salt blisters” is seen on a number of salt islands

Texas Salt Domes--Aspects, Affecting Disposal of Toxic-Chemical Waste in Solution-Mined Caverns

This report represents Phase II of a one-year contract aimed at analyzing technical considerations linked to the potential isolation of toxic chemical waste within solution-mined caverns situated in Texas salt domes. A key objective of Phase II research was to characterize the properties of salt domes that could impact this form of waste disposal.Bureau of Economic Geolog

The Internal Structure of Model and Natural Salt Domes

To enhance our understanding of the internal structure of salt stocks, we conducted 30 centrifuge experiments that produced hundreds of model diapirs under artificial acceleration generally equivalent to 1,200 times that of normal gravity. Most of these experiments were geometrically and dynamically scaled to be equivalent to U.S. Gulf Coast salt domes. The domes were modeled under static overburdens and, for the first time, under aggrading and prograding overburdens. This report focuses on the internal structure of mushroom-shaped domes, which theoretically exist in nature and are demonstrated in natural examples in the U.S. Gulf Coast, Canada, and West Germany. The experimental results enable the extremely complex internal structure of mushroom-shaped salt domes to be recognized and understood. This recognition is vital because a mushroom structure would threaten the integrity of a hypothetical repository by creating a plumbing system composed of country rocks infolded from below the diapir cap and extending to near the dome center.Bureau of Economic Geolog

Geology and Geohydrology of the East Texas Basin

The investigations in the East Texas Basin are part of the broader salt dome studies underway in the Gulf Coast Interior Salt Basin of Texas, Louisiana, and Mississippi, constituting one regional element of the national Nuclear Waste Repository Program. The U.S. Department of Energy (DOE) aims to select one salt site for site-specific evaluation as a nuclear waste repository. This report focuses on the salt dome program in East Texas and outlines some preliminary conclusions reached on dome suitability during FY1980. The 1980 program to investigate the tectonic, geologic, and hydrogeologic stability of salt domes in the East Texas Basin was divided into four subprograms: 1. Subsurface geology. 2. Surficial geology, remote sensing, and geomorphology. 3. Hydrogeology. 4. Salt dome characteristics. Integration of the results from these four subprograms will determine the general suitability of salt domes in the East Texas Basin for further evaluation as a potential nuclear waste repository and will provide information on specific candidate domes in the East Texas Basin.Bureau of Economic Geolog

Evaluating the Potential of East Texas Salt Domes for Isolation of Nuclear Waste

Since January 1978, the Bureau of Economic Geology has been evaluating the potential for using a salt dome in the East Texas Basin as a repository for nuclear waste isolation. This report is a brief summary of work accomplished within Year I. Using the dome selection criteria of Brunton and others (1977), Kreitler and others (1978) selected Oakwood, Keechi, and Palestine salt domes as possible sites for a nuclear waste repository. The problem of depositing nuclear wastes into an East Texas salt dome contains two critical questions: (1) Are the domes still growing (tectonic stability)? (2) Are the domes dissolving, and what is the rate of dissolution (hydrologic stability)? These two questions are being asked on a dome-specific and regional scale. The long-term suitability of a dome cannot be ascertained until it is placed in a regional context. This necessitates regional as well as site-specific studies. The approach includes three subprograms: (1) subsurface geology, (2) hydrogeology, and (3) surficial geology and remote sensing. The subsurface geology program investigates dome size and shape, the geology immediately around the dome, and the infilling of the East Texas Basin over geologic time and how this basin filling affected the growth of the domes. The surficial geology and remote sensing program addresses the problem of potential dome growth during the Quaternary. Typical questions examined in this program include: have Pleistocene terraces been uplifted or warped, has there been any fault movement in the Pleistocene, and are there any movements reflected in lineation patterns around domes anomalous to regional patterns or indicated by drainage networks? The hydrogeology program evaluates the hydrologic stability of the domes with the following objectives: What are the rates and directions of regional groundwater flow? What are the ages of these groundwaters? How does groundwater flow around a salt dome? What are the rates of salt solution? Does the caprock prevent salt dissolution? This document represents a progress report and is not a final statement on the Bureau of Economic Geology's position on the suitability of salt domes in the East Texas Basin for waste isolation. The observations and ideas presented in this document therefore represent a status report and may be subject to change as more information and concepts are developed.Bureau of Economic Geolog