Hostname: page-component-cd9895bd7-hc48f Total loading time: 0 Render date: 2024-12-27T01:33:27.008Z Has data issue: false hasContentIssue false

Wipp Site Studies: Secondary Selenite Veins in the Rustler Formation and Dewey Lake Red Beds

Published online by Cambridge University Press:  28 February 2011

D. G. Brookins
Affiliation:
Geol. Dept., Univ. New Mexico, Albuquerque, NM 87131
S. J. Lambert
Affiliation:
Sandia National Labs, Albuquerque, NM 87185
Get access

Abstract

Defense-generated transuranic (TRU) waste will be stored at WIPP in the bedded halite of the Salado Formation (Permian), which is overlain by the impure Permian evaporites of the Rustler Formation and the Dewey Lake Red Beds. Both the Rustler and Dewey Lake contain abundant to less common secondary selenite veins of uncertain origin, and dissolution zones occur in the Rustler. The Rustler Formation also contains two dolomite aquifers, the Magenta and Culebra members. The purpose of this study is to determine whether vein selenite is locally derived, or has been introduced in moving groundwater solutions. We have used Sr isotopic studies and REE, U and other trace element data to address the problem. The Sr isotopic data show that neither the Salado nor Rustler anhydrites have exchanged with secondary sources of Sr, and this is supported by the REE and U data. Further, selenite veins from the Rustler possess Sr isotopic compositions identical to the Rustler, indicating local origin, and this is also supported by the U and REE data. Selenite veins from the Dewey Lake Red Beds possess Sr isotopic compositions closer to surface caliche deposits, and may contain near-surface derived Sr. U and REE data show more scatter and evidence for extrinsic sources than the vein/host-rock pairs from the Rustler. Sr isotopic compositions of the Magenta and Culebra indicate that the Magenta has undergone less water/rock interaction than the Culebra. Collectively, the data argue for more possible surface or near-surface water/rock interactions in the Dewey Lake Red Beds than in the Rustler Formation; such interactions in the Salado Formation have been minimal.

Type
Research Article
Copyright
Copyright © Materials Research Society 1988

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

1. Powers, D.D., Lambert, S.J., Shaffer, S.E., Hill, L.R., and Weart, W.D., editors., SAND 78–1596, 1979.Google Scholar
2. Brookins, D.G., Geochemical Aspects of Radioactive Waste Disposal, Springer-Verlag, Inc., New York and Heidelberg, 1984, p. 347.Google Scholar
3. Faure, G., Principles of isotope Geology, 2nd Ed., Wiley & Sons, New York, 1986, p. 589.Google Scholar
4. Minor, M.M., Hensley, W.K., Denton, M.M., and Garcia, S., LA-UR-81–1810, 1981, p. 14.Google Scholar
5. Burke, W.H., Denison, R.E., Hetherington, E.A., Koepnick, R.B., Nelson, N.F., and Otto, J.B., Geology, 10, p. 516 (1982).Google Scholar
6. Brookins, D.G., Sand 86–7168, in preparation.Google Scholar