Saturation fractured tuff

Tsang, Y.W., K. Huang, and G. S. Bodvarsson. Estimation of the Heterogeneity of Fracture Permeability by Simultaneous Modeling of Multiple Air-Infection Tests in Partially Saturated Fractured Tuff. Dynamics of Fluids in Fractured Rock. Geophysical Monograph 122, American Geophysical Union. 2000... 

Birkholzer, J.T. Tsang, Y.W. 2000. Modeling the thermal-hydrologic processes in a large-scale underground heater test in partially saturated fractured tuff. Water Resources Research, 36(6) pp. 1431-1447. 

The evolution of the chemical regime in the unsaturated zone surrounding a heat source is closely related to the spatial distribution of temperature and the transport of water and vapor. An important aspect of the unsaturated fractured tuff at Yucca Mountain is that the highly permeable fractures are nearly dry, whereas the low permeability and porosity rock matrix has a water saturation of about 90 percent. Thus, heating of the rock induces boiling of the matrix pore water, transport of water vapor into fractures, and condensation along fracture walls. 

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