TY - Generic T1 - Granite as a geothermal resource in the Northeast T2 - Abstracts with Programs - Geological Society of America Y1 - 2012 A1 - John Michael Rhodes A1 - Koteas, G. Christopher A1 - Stephen B Mabee KW - #StaffPubs KW - Cammenallis Pluton KW - Cornwall England KW - Eastern U.S. KW - Economic geology, geology of energy sources 29A KW - energy sources KW - England KW - Europe KW - geothermal energy KW - geothermal exploration KW - granites KW - Great Britain KW - heat flow KW - hydrothermal conditions KW - igneous rocks KW - intrusions KW - Northeastern U.S. KW - plutonic rocks KW - plutons KW - thermal conductivity KW - United Kingdom KW - United States KW - Western Europe AB - In the absence of volcano-derived hydrothermal activity and high heat flow, granitic plutons provide an alternative geothermal resource from which heat may be usefully extracted. Compared with other crustal rocks, granites contain higher concentrations of the heat producing elements (K, U, Th). Additionally, they are more homogeneous and have simpler fracture systems than surrounding country rock, allowing for stimulation through hydro-fracking of large (>1 km (super 3) ) geothermal reservoirs. However, not all granites are created equal! Those with heat production > 5 mu W/m (super 3) , or with deep batholithic roots, are the most promising. Estimated temperatures at a given depth are related to the heat production, thickness and thermal conductivity of the granite. For example, the Carnmenellis Pluton in Cornwall, England (which will be drilled in 2012) is estimated to have temperatures in excess of 170 degrees C at a depth of 5 km, which is sufficient for co-production of electricity and hot water for heating. More importantly, granite bodies that are buried beneath thick sequences of thermally insulating sediments are also potential geothermal targets. Most successful examples to date include the Soultz sur Foret project in France, with temperatures of 200 degrees C at a depth of 5 km. (and which is currently producing electricity), Innamincka, Australia, with temperatures of 250 degrees C at a depth of 4 km. (which will be producing in 2012), and the seismically ill-fated project in Basel, Switzerland. Surely, if such projects involving the geothermal potential of granites, can succeed elsewhere, they can succeed here in the granite-rich Northeast? The geothermal potential of the Conway Granite, NH has long been recognized. Other possibilities include the Fitchburg Pluton, MA, and granites buried beneath the Carboniferous sediments of the Narragansett Basin and the Triassic sediments of the Connecticut River valley. JF - Abstracts with Programs - Geological Society of America PB - Geological Society of America (GSA) : Boulder, CO, United States CY - United States VL - 44 SN - 00167592 UR - https://gsa.confex.com/gsa/2012NE/finalprogram/abstract_200603.htm IS - 22 N1 - Accession Number: 2012-090078; Conference Name: Geological Society of America, Northeastern Section, 47th annual meeting; Hartford, CT, United States; Conference Date: 20120318; Language: English; Coden: GAAPBC; Collation: 1; Collation: 76; Publication Types: Abstract Only; Serial; Conference document; Updated Code: 201247; Monograph Title: Geological Society of America, Northeastern Section, 47th annual meeting; Monograph Author(s): Anonymous; Reviewed Item: Analytic JO - Abstracts with Programs - Geological Society of America ER - TY - Generic T1 - Identifying and examining potential geothermal resources in non-traditional regions, examples from the northeastern U.S. T2 - Abstracts with Programs - Geological Society of America Y1 - 2011 A1 - Koteas, G. Christopher A1 - John Michael Rhodes A1 - Stephen B Mabee A1 - Goodhue, Nathaniel A1 - Adams, Sharon A. KW - #StaffPubs KW - Andover Granite KW - Eastern U.S. KW - Economic geology, geology of energy sources 29A KW - exploitation KW - exploration KW - Fall River Granite KW - field studies KW - geochemistry KW - geothermal energy KW - identification KW - mapping KW - massachusetts KW - models KW - Northeastern U.S. KW - overburden KW - resources KW - sampling KW - southeastern Massachusetts KW - spectra KW - structural analysis KW - technology KW - temperature KW - United States KW - whole rock KW - X-ray fluorescence spectra AB - 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. JF - Abstracts with Programs - Geological Society of America PB - Geological Society of America (GSA) : Boulder, CO, United States CY - United States VL - 43 SN - 00167592 IS - 55 N1 - 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 JO - Abstracts with Programs - Geological Society of America ER - TY - Generic T1 - Implications of diurnal river fluctuations on mass transport in a valley-fill aquifer T2 - Abstracts with Programs - Geological Society of America Y1 - 2006 A1 - Brandon J Fleming A1 - David F Boutt A1 - Stephen B Mabee KW - #StaffPubs KW - aquifers KW - BEDROCK KW - clastic sediments KW - controls KW - diffusion KW - diurnal variations KW - drainage KW - drift KW - Eastern U.S. KW - Environmental geology 22 KW - floods KW - fluctuations KW - geochemical cycle KW - geologic hazards KW - ground water KW - measurement KW - mixing KW - models KW - Northeastern U.S. KW - numerical models KW - nutrients KW - pollution KW - processes KW - pumping KW - quantitative analysis KW - residence time KW - sediments KW - shallow aquifers KW - surface water KW - three-dimensional models KW - tracers KW - transport KW - United States KW - valleys KW - water pollution KW - water resources KW - water wells AB - Aquifers located in isolated stratified drift deposits in the northeastern portion of the US are extremely fragile and important groundwater resources. These aquifers, when restricted to bedrock valleys, are often strongly coupled to significant surface water drainage systems. In northwestern Massachusetts, surface water associated with the Deerfield River watershed is highly regulated by dams to protect against flooding and to generate hydroelectric power. Regular releases of water from these dams cause diurnal fluctuations in river stage. In a previous study performed by the USGS, measurements from two clusters of wells show a significant response to river stage fluctuations in the aquifer. Fluctuations in river stage and resulting changes in head levels in the aquifer cause a switch from a losing to a gaining stream. The flow reversals have implications for mass transport and nutrient cycling within the hyporheic zone. In this paper we investigate the physical hydrologic controls on mass transport in the shallow aquifer. Using a coupled groundwater flow and transport code, we built a quasi three dimensional transient numerical model to approximate the head changes in the aquifer caused by the stage fluctuations in the river. Flow velocities and residence times were estimated in the aquifer for a variety of flow conditions. The mixing process driven by the aquifer head changes were quantified in the proximity of the hyporheic zone and shown to significantly influence both vertical and horizontal flow velocities in a region close to the stream-aquifer boundary. The diurnal river stage changes also appear to influence farfield hydrologic conditions and potentially hydrologically isolate the river and hyporheic zone. To further investigate these mixing processes we applied a mass transport code with conservative tracers to the aquifer. Fluctuation of the river stage combined with the heterogeneous nature of the aquifer creates a pumping mechanism that creates excess mixing within shallow portions of the aquifer. Aquifer dispersivity and molecular diffusion both contribute to the anomalous mixing modeled in the shallow aquifer. Mixing driven by stream stage changes has important implications for nutrient cycling as well as contaminant transport in the shallow aquifer. JF - Abstracts with Programs - Geological Society of America PB - Geological Society of America (GSA) : Boulder, CO, United States CY - United States VL - 38 SN - 00167592 UR - https://gsa.confex.com/gsa/2006AM/finalprogram/abstract_115285.htm IS - 77 N1 - Accession Number: 2010-061334; Conference Name: Geological Society of America, 2006 annual meeting; Philadelphia, PA, United States; Conference Date: 20061022; Language: English; Coden: GAAPBC; Collation: 1; Collation: 468; Publication Types: Abstract Only; Serial; Conference document; Updated Code: 201034; Monograph Title: Geological Society of America, 2006 annual meeting; Monograph Author(s): Anonymous; Reviewed Item: Analytic JO - Abstracts with Programs - Geological Society of America ER - TY - JOUR T1 - Improving seismic hazard assessment in New England through the use of surficial geologic maps and expert analysis JF - Special Paper - Geological Society of America Y1 - 2012 A1 - Becker, Laurence R. A1 - Patriarco, Steven P. A1 - Marvinney, Robert G. A1 - Thomas, Margaret A. A1 - Stephen B Mabee A1 - Fratto, Edward S. KW - #StaffPubs KW - civil engineering KW - earthquakes KW - Eastern U.S. KW - Engineering geology 30 KW - Environmental geology 22 KW - geologic hazards KW - mitigation KW - natural hazards KW - New England KW - Northeastern U.S. KW - risk assessment KW - risk management KW - safety KW - seismic risk KW - seismicity KW - United States AB - (GSA Special Paper) In New England, earthquakes pose a risk to the built environment. Emergency preparedness and mitigation planning are prudent in this region as older unreinforced masonry buildings and numerous critical facilities are common. New England state geological surveys cooperate with the Northeast States Emergency Consortium (NESEC) to improve risk communication with emergency managers. To that end, Connecticut, Maine, Massachusetts, and Vermont employed surficial geologic maps, deglaciation history, knowledge of the glacial stratigraphy, and professional judgment to reclassify surficial geologic material units into one of the five National Earthquake Hazards Reduction Program (NEHRP) site classifications (A, B, C, D, and E). These new classifications were used as a substitute for the HAZards U.S. Multi-Hazard (HAZUS-MH) site class value of "D," which is used throughout New England as a default value. In addition, coding of surficial geologic materials for the five NEHRP site classifications was compared with classifications using the Wald methodology, a method that uses a slope analysis as a proxy for shear-wave velocity estimates. Comparisons show that coding to site classes using the Wald methodology underestimates categories A (high-velocity shear-wave materials, least relative hazard) and E (lowest-velocity shear-wave materials, greatest relative hazard) when evaluated side by side with coding done with the aid of surficial geologic maps. North of the glacial limit, derangement of drainage resulted in extensive ponding of meltwaters and the subsequent deposition of thick sequences of lacustrine mud. Inundation by the sea immediately following deglaciation in New England resulted in the deposition of spatially extensive and locally thick sequences of glacial marine mud. Surficial geologic maps better capture this circumstance when compared with the Wald topographic slope analysis. Without the use of surficial geologic maps, significant areas of New England will be incorrectly classified as being more stable than the site conditions that actually exist. By employing surficial geologic information, we project an improved accuracy for HAZUS-MH earthquake loss estimations, providing local and regional emergency managers with more accurate information for locating and prioritizing earthquake planning, preparedness, and mitigation projects to reduce future losses. PB - Geological Society of America (GSA) : Boulder, CO, United States CY - United States VL - 493 SN - 007210779780813724935 UR - http://specialpapers.gsapubs.org/content/493/221.abstract N1 - Accession Number: 2013-034008; Conference Name: Geological Society of America, 2010 annual meeting; Denver, CO, United States; Conference Date: 20101031; Language: English; Coden: GSAPAZ; Collation: 22; Collation: 221-242; Publication Types: Serial; Conference document; Updated Code: 201321; Illustration(s): illus. incl. 6 tables, geol. sketch maps; Number of References: 36; Monograph Title: Recent advances in North American paleoseismology and neotectonics east of the Rockies; Monograph Author(s): Cox, Randel Tom [editor]; Tuttle, Martitia P. [editor]; Boyd, Oliver S. [editor]; Locat, Jacques [editor]; Reviewed Item: Analytic JO - Special Paper - Geological Society of America ER -