Hydrologic inferences from strontium isotopes in pore water from the unsaturated zone at Yucca Mountain, Nevada
Calcite is ubiquitous at Yucca Mountain, occurring in the soils and as fracture and cavity coatings within the volcanic tuff section. Strontium is a trace element in calcite, generally at the tens to hundreds of ppm level. Because calcite contains very little rubidium and the half-life of the {sup 87}Rb parent is billions of years, the {sup 87}Sr/{sup 86}Sr ratios of the calcite record the ratio in the water from which the calcite precipitated. Dissolution and reprecipitation does not alter these compositions so that, in the absence of other sources of strontium, one would expect the strontium ratios along a flow path to preserve variations inherited from strontium in the soil zone. Strontium isotope compositions of calcites from various settings in the Yucca Mountain region have contributed to the understanding of the unsaturated zone (UZ), especially in distinguishing unsaturated zone calcite from saturated zone calcite. Different populations of calcite have been compared, either to group them together or distinguish them from each other in terms of their strontium isotope compositions. Ground water and perched water have also been analyzed; this paper presents strontium isotope data obtained on pore water.
- Research Organization:
- US Geological Survey, Denver, CO (United States)
- Sponsoring Organization:
- USDOE Assistant Secretary for Human Resources and Administration, Washington, DC (United States)
- DOE Contract Number:
- AI08-92NV10874
- OSTI ID:
- 290862
- Report Number(s):
- CONF-971224-; ON: DE99000989; TRN: 99:003822
- Resource Relation:
- Conference: Field testing and associated modeling (FTAM) of potential high-level nuclear waste geologic disposal sites workshop, Berkeley, CA (United States), 15-16 Dec 1997; Other Information: PBD: [1997]
- Country of Publication:
- United States
- Language:
- English
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