@proceedings {295, title = {Fracture characterization; valuable inputs for modeling groundwater flow in fractured bedrock}, volume = {28}, year = {1996}, note = {Accession Number: 1996-065028; Conference Name: Geological Society of America, Northeastern Section, 31st annual meeting; Buffalo, NY, United States; Conference Date: 19960321; Language: English; Coordinates: N364500N374500W1190100W1203800; Coden: GAAPBC; Collation: 1; Collation: 77; Publication Types: Abstract Only; Serial; Conference document; Updated Code: 199620; Monograph Title: Geological Society of America, Northeastern Section, 31st annual meeting; Monograph Author(s): Anonymous; Reviewed Item: Analytic}, month = {1996/02/01/}, pages = {77 - 77}, publisher = {Geological Society of America (GSA) : Boulder, CO, United States}, address = {United States}, keywords = {$\#$StaffPubs, BEDROCK, boreholes, California, discontinuities, experimental studies, field studies, fractured materials, fractures, ground water, Hydrogeology 21, Madera County California, models, movement, observation wells, Raymond California, site exploration, spatial distribution, transmissivity, United States, wells}, isbn = {00167592}, author = {Stephen B Mabee and Hardcastle, Kenneth C.} } @proceedings {300, title = {Identifying and examining potential geothermal resources in non-traditional regions, examples from the northeastern U.S.}, volume = {43}, year = {2011}, note = {Accession Number: 2012-083486; Conference Name: Geological Society of America, 2011 annual meeting; Minneapolis, MN, United States; Conference Date: 20111009; Language: English; Coden: GAAPBC; Collation: 1; Collation: 40; Publication Types: Abstract Only; Serial; Conference document; Updated Code: 201244; Monograph Title: Geological Society of America, 2011 annual meeting; Monograph Author(s): Anonymous; Reviewed Item: Analytic}, month = {2011/10/01/}, pages = {40 - 40}, publisher = {Geological Society of America (GSA) : Boulder, CO, United States}, address = {United States}, abstract = {The search for geothermal resources is rapidly expanding into tectonic regions that have not been previously considered to be suitable for exploitation. Many of these regions, such as the northeastern U.S., have never been the site of extensive geophysical investigations and have few deep borehole temperature measurements. Nevertheless, large portions of the northeastern U.S. are underlain by granitic bedrock that may be a productive energy source by applying enhanced geothermal technologies. In the absence of traditional reconnaissance data, we utilize field studies and sampling together with geochemical analysis to develop models of geothermal resources that can be tested against data from deep boreholes. Heat production is calculated from the measured density of the samples, the concentrations of K, U, and Th from whole-rock geochemical analysis via X-ray fluorescence, and established radiogenic heat production values. Models for a particular area can then be generated by calculating depth-specific temperatures using heat production, measured thermal conductivity for each sample, and assumptions related to local stratigraphy and regional heat flow. Mapping and structural extrapolation are used to establish the subsurface characteristics at a study site and are combined with the thermal and chemical characteristics of contact rocks and overburden materials. Two examples of the application of this technique are the Fall River granite at the margin of the Narragansett Basin in southeastern Massachusetts and the Andover Granite in northeastern Massachusetts. Thermal models of the Fall River Pluton indicate average temperatures of 71 degrees C at depths of 4 km and 97 degrees C at 6 km. Average temperatures increase to 107 degrees C and 132 degrees C, respectively, when a 2 km thick sediment package is modeled overlying the granite. The Andover Granite, which is not associated with a sedimentary basin and is in a more structurally complex configuration, yields an average temperature of 74 degrees C at a depth of 4 km and 101 degrees C at 6 km. While this approach to modeling temperature-depth profiles requires some regional heat flow assumptions, the application of mapping and structural analysis with geochemistry and thermal conductivity studies can be an important reconnaissance tool for identifying non-traditional geothermal resources.}, keywords = {$\#$StaffPubs, Andover Granite, Eastern U.S., Economic geology, geology of energy sources 29A, exploitation, exploration, Fall River Granite, field studies, geochemistry, geothermal energy, identification, mapping, massachusetts, models, Northeastern U.S., overburden, resources, sampling, southeastern Massachusetts, spectra, structural analysis, technology, temperature, United States, whole rock, X-ray fluorescence spectra}, isbn = {00167592}, author = {Koteas, G. Christopher and John Michael Rhodes and Stephen B Mabee and Goodhue, Nathaniel and Adams, Sharon A.} } @article {270, title = {Analyzing outcrop-scale fracture features to supplement investigations of bedrock aquifers}, journal = {Hydrogeology Journal}, volume = {5}, year = {1997}, note = {Accession Number: 1998-019185; Language: English; Language of Summary: French; Spanish; Coordinates: N364500N374500W1190100W1203800; Collation: 16; Publication Types: Serial; Updated Code: 199808; Illustration(s): illus. incl. 3 tables, sketch maps; Number of References: 28; Reviewed Item: Analytic}, month = {1997/01/01/}, pages = {21 - 36}, publisher = {Verlag Heinz Heise : Hanover, Federal Republic of Germany}, address = {Federal Republic of Germany}, abstract = {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.}, keywords = {$\#$StaffPubs, aquifers, BEDROCK, boreholes, California, dip fractures, field studies, fractures, framework silicates, ground water, hydrodynamics, Hydrogeology 21, laumontite, Madera County California, mapping, mineralization, movement, Raymond California, roughness, silicates, United States, zeolite group}, isbn = {1431217414350157}, url = {http://link.springer.com/article/10.1007/s100400050106}, author = {Stephen B Mabee and Hardcastle, Kenneth C.} }