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
