Multiple episodes of zeolite deposition in fractured silicic tuff
Fractures in silicic tuffs above the water table at Yucca Mountain, Nevada, USA contain two morphologies of heulandite with different compositions. Tabular heulandite is zoned, with Sr-rich cores and Mg-rich rims. Later prismatic heulandite is nearly the same composition as the more magnesian rims. Heulandite and stellerite may occur between layers of calcite, and calcite occurs locally between generations of heulandite. Thermodynamic modeling, using estimated thermodynamic data and observed chemical compositions for heulandite and stellerite, shows that stellerite is the favored zeolite unless Ca concentrations are reduced or Mg and/or Sr concentrations are significantly elevated above current Yucca Mountain waters.
- Research Organization:
- Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
- Sponsoring Organization:
- USDOE, Washington, DC (United States)
- DOE Contract Number:
- W-7405-ENG-36
- OSTI ID:
- 62620
- Report Number(s):
- LA-UR-95-871; CONF-950888-1; ON: DE95009430
- Resource Relation:
- Conference: International symposium on water-rock interaction, Vladivostok (Russian Federation), 13-28 Aug 1995; Other Information: PBD: [1995]
- Country of Publication:
- United States
- Language:
- English
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