K.C. Vorthmann
Because of the properties of rock salt it has been used and is being investigated for further use as a hazardous waste repository. Some salt diapirs in Germany in particular are being targeted to be used for nuclear waste disposal. One aspect that has not been looked at but that needs to be considered when determining if a salt diapir is appropriate for waste disposal is the sinking of higher density blocks, specifically anhydrite, in the diapir after it appears to have become stable. This movement in the diapir could lead to further deformation of the diapir and could possibly destroy a repository built within the structure.
Figure 1: A model of a salt diapir with entrained segments of higher density sediment. Koyi (2001)
Figure 2: Models of initial (A) and final (B) phases in a salt diapir illustrating internal flow due to the sinking of higher density blocks of sediment within the diapir. Deformation occurs not only near the blocks but also at least a kilometer away, according to the diagram. Koyi (2001)
Outline:
Introduction
Conclusion
References:
Koyi, H.A., 2001, Modeling the influence of sinking anhydrite blocks on salt diapirs targeted for hazardous waste disposal, Geology, v. 29, no. 5, p. 387-390.
Lundgren, L.W., 1999, Environmental Geology, Upper Saddle River, NJ: Prentice-Hall.
Merritts, D., DeWet, A., and Menking, K., 1998, Environmental Geology, New York: W.H. Freeman.
Montgomery, C.W., 1995, Environmental Geology, Dubuque, IA: Wm. C. Brown.
Spencer, E.W., 1969, Introduction to the Structure of the Earth, New York: McGraw-Hill.
Twiss, R.J. and Moores, E.M., 1992, Structural Geology, New York: W.H. Freeman.
U.S. Department of Energy, Why salt was selected as a disposal medium: Waste Isolation Pilot Plant, http://www.wipp.carlsbad.nm.us/ fctshts/whysalt.pdf (4 April 2002).