Lithological Conditions at the Box Canyon Site: Results of Drilling, Coring and Open Borehole Measurements 1995-1997 Data Report

DOE faces the remediation of several contaminated sites in unsaturated fractured basalt where organic and radioactive wastes have migrated downward through fracture pathways that are difficult, if not impossible, to detect. Perched water zones located above zones of low permeability (massive basalt) create a complicated system of hydraulic baffles. Because of these large scale heterogeneities, the characterization of the lithology of the rock and the geometry of the subsurface fracture pattern is a crucial step in the development of a conceptual model of fluid flow and chemical transport, and eventually the design of a remediation system. The purpose of this data report is to compile and document the results of drilling and lithological studies conducted in open boreholes at the Box Canyon site. Lithological templates are included for each well and contain data such as drilling date, drilling method, logging method, well coordinates, Lithological log, gamma measurements, caliper measurements, core run and recovery depth, vesicular intervals, single fracture depths and descriptions, fracture zone depth and descriptions, and general comments about the borehole lithology. The lithological features were mapped for each borehole. The gamma and caliper measurements are presented as separate plots using greater resolution. Color core photos and core descriptions are also included. TV logging was used to map the lithology of the boreholes that were not cored (E, R, and T wells). This information will be further used to create a comprehensive lithological model of the subsurface. The TV logging of cored wells was viewed to compare the resolution and accuracy of TV logging to core logging. The TV logging method accurately showed large scale features such as zones of vesicularity, large fractures, fracture zones, rubble zones, and massive basalt zones, but it was difficult to detect hairline fractures, fracture orientation, and mineralization of fractures. Also, all depth measurements in increments less than 1 ft are estimated. TV logging is not as precise as logging directly from the core, but it is useful for mapping the major lithological features