TY  - JOUR
AU  - Vogel, J. C.
AU  - Talma, A. S.
AU  - Heaton, T. H. E.
AU  - Kronfeld, J.
PY  - 1999//
TI  - Evaluating the rate of migration of an uranium deposition front within the Uitenhage Aquifer
JO  - Journal of Geochemical Exploration
SP  - 269
EP  - 276
VL  - 66
IS  - 1
KW  - redox changes in aquifer
KW  - sandstone-type uranium deposit
KW  - South Africa
KW  - uranium series
N2  - The solubility of uranium in groundwater is very sensitive to changes in redox conditions. Many secondary (sandstone-type) uranium deposits have been formed when soluble U has precipitated after encountering reducing conditions in the subsurface. In the groundwater of the Uitenhage Aquifer (Cape Province, South Africa), 238U-series isotopes were used to assist in studying the history of the reducing barrier. Uranium isotopes were used to determine the present position of the barrier. Radium and radon were used to evaluate the path of migration that the front of the oxygen depletion zone has taken over the past 105 years. During this time the reducing barrier has moved, leaving in its wake a trail of U in various stages of secular equilibrium with its daughter 230Th. The 226Ra daughter of 230Th is not very mobile. Its growth upon the aquifer wall is reflected in the Rn content of the water. This in turn, due to the relatively great age of the water, indicates the extent of the 230Th ingrowth (from precipitated U) that took place before the barrier migrated.
SN  - 0375-6742
UR  - https://www.sciencedirect.com/science/article/pii/S037567429900031X
N1  - exported from refbase (http://www.uhydro.de/base/show.php?record=126), last updated on Fri, 26 Jan 2024 13:19:04 +0100
ID  - Vogel_etal1999
ER  -