%0 Conference Proceedings %B Abstracts with Programs - Geological Society of America %D 1999 %T Factors influencing groundwater inflows in a newly constructed cross-strike tunnel, eastern Massachusetts; 4, Occurrence and characterization of groundwater inflows %A Williams, Katherine W. %A Stephen B Mabee %A Hardcastle, Kenneth C. %A Curry, Patrick J. %K #StaffPubs %K BEDROCK %K boreholes %K characterization %K design %K discharge %K eastern Massachusetts %K flows %K fractures %K Framingham Quadrangle %K ground water %K Hydrogeology 21 %K massachusetts %K movement %K Natik Quadrangle %K occurrence %K outcrops %K surface water %K topography %K tunnels %K United States %X All occurrences of groundwater inflows in a 9 km long, 5-m diameter section of tunnel, 70 to 90 m below grade, were compared with subsurface fracture density, bedrock topography, surface topography, type of surficial deposits, proximity to surface water bodies, and the geographic distribution (domains; Mabee et al., this volume) of surface and subsurface fractures. Subsurface fracture density was calculated for the 320 fractures (through-going fractures) that intersect the entire circumference of the tunnel. Bedrock topography was determined using bore hole data collected during the design phase of the tunnel project. Surface topography is from 1:25,000 scale topographic maps and surficial geology is based on maps of the Framingham and Natick Quadrangles. Seven surface water bodies, primarily brooks and rivers, overlie the tunnel. Five surface fracture domains are based on 1513 fracture measurements collected from 21 outcrops within 3 km of the tunnel. In the tunnel, 413 fractures (all fractures, dips>45 degrees ) comprise seven subsurface fracture domains. High groundwater inflows generally correlate with areas of high subsurface fracture density and where four or more subsurface fracture domains overlap. In addition, high groundwater inflows are also generally located near surface water bodies and below permeable surficial deposits and topographic depressions, especially those with corresponding lows in the bedrock surface. Moreover, subsurface structures which correlate with prominent surface fracture domains produce the highest volume of groundwater inflow. However, not all tunnel sections exhibiting high fracture density and overlapping fracture domains exhibit high groundwater inflows. Also, there is no correlation between areas where two or more surface fracture domains overlap and the volume of groundwater discharging to the tunnel. %B Abstracts with Programs - Geological Society of America %I Geological Society of America (GSA) : Boulder, CO, United States %C United States %V 31 %P 348 - 348 %8 1999/01/01/ %@ 00167592 %G eng %N 77 %! Abstracts with Programs - Geological Society of America %0 Conference Proceedings %B Abstracts with Programs - Geological Society of America %D 1996 %T Fracture characterization; valuable inputs for modeling groundwater flow in fractured bedrock %A Stephen B Mabee %A Hardcastle, Kenneth C. %K #StaffPubs %K BEDROCK %K boreholes %K California %K discontinuities %K experimental studies %K field studies %K fractured materials %K fractures %K ground water %K Hydrogeology 21 %K Madera County California %K models %K movement %K observation wells %K Raymond California %K site exploration %K spatial distribution %K transmissivity %K United States %K wells %B Abstracts with Programs - Geological Society of America %I Geological Society of America (GSA) : Boulder, CO, United States %C United States %V 28 %P 77 - 77 %8 1996/02/01/ %@ 00167592 %G eng %N 33 %! Abstracts with Programs - Geological Society of America %0 Journal Article %J Hydrogeology Journal %D 1997 %T Analyzing outcrop-scale fracture features to supplement investigations of bedrock aquifers %A Stephen B Mabee %A Hardcastle, Kenneth C. %K #StaffPubs %K aquifers %K BEDROCK %K boreholes %K California %K dip fractures %K field studies %K fractures %K framework silicates %K ground water %K hydrodynamics %K Hydrogeology 21 %K laumontite %K Madera County California %K mapping %K mineralization %K movement %K Raymond California %K roughness %K silicates %K United States %K zeolite group %X A case study was conducted of 79 outcrops within 150 meters of the nine, 7590 m deep boreholes at the Lawrence Berkeley Laboratory (LBL) Fracture Hydrology Field Site in Raymond, California, USA, in order to make preliminary comparisons between surface fracture data and geophysical and hydrologic testing conducted in the boreholes. The orientation, trace length, spacing, roughness, planarity, associated mineralization, and domains (the geographic distribution of specific fracture sets) of 471 fractures were measured. Five families of steeply-dipping fractures and one family of shallow dipping fractures comprise 75 percent of the data and trend 52, 62, 130, 147, 173, and 35, respectively. The geographic distributions (domains) of the families, however, show the well field to be within the domains of the 62-, 173- and 35-trending families. The steeply-dipping fractures detected in the boreholes by LBL via acoustic televiewer logging trend about 65, 173, and 30 corroborating the findings of the fracture-domain analysis. Results indicate that the boreholes are located within a laumontite-mineralized area, including a steeply-dipping, 160-trending zone, 520 cm wide, of laumontite-rich pods that transects the boreholes. Independent hydrologic tests by LBL revealed a 160-trending barrier to groundwater flow between some of the boreholes, precisely where the 160-trending zone of laumontite-mineralized pods was mapped. %B Hydrogeology Journal %I Verlag Heinz Heise : Hanover, Federal Republic of Germany %C Federal Republic of Germany %V 5 %P 21 - 36 %8 1997/01/01/ %@ 1431217414350157 %G eng %U http://link.springer.com/article/10.1007/s100400050106 %N 4 %! Hydrogeology Journal