%0 Conference Proceedings %B Abstracts with Programs - Geological Society of America %D 2012 %T Deep geothermal resource potential in Connecticut; progress report %A Gagnon, Teresa K. %A Koteas, G. Christopher %A Thomas, Margaret A. %A Stephen B Mabee %A John Michael Rhodes %K #StaffPubs %K Connecticut %K Economic geology, geology of energy sources 29A %K energy sources %K geothermal energy %K geothermal exploration %K geothermal gradient %K granites %K heat flow %K igneous rocks %K New England %K plutonic rocks %K temperature %K thermal conductivity %K United States %X The Connecticut and Massachusetts Geological Surveys are collaborating on a National Geothermal Data Project funded by the US Department of Energy through the Association of American State Geologists.Geothermal resources in Connecticut (CT) to date have been exploited using near surface ground source heat pump technology. This is the first investigation of CT deep geothermal resources. Many CT granitoids contain heat producing elements. The goal is to identify geologic units capable of producing enough heat, at reasonable drilling depths, to operate a viable geothermal power plant. Target rock units must contain enough uranium, thorium and potassium (U/Th/K) in combination with heat generated through the natural geothermal gradient of the Earth to generate electricity and co-produced direct heating. Heat at depth can be concentrated by an overlying insulating layer of sedimentary rocks and glacial sediments. 27 CT bedrock units were selected for sampling using existing mapping. 120 samples were analyzed using X-Ray Fluorescence Spectrometry. Heat production values (HPVs) at or greater than 4 mu W/m (super 3) were considered to be of interest. Values ranging from 4 to 18 mu W/m (super 3) were calculated for 7 of the 27 rock units. Elevated concentrations of thorium, ranging from 10.5 ppm to 245 ppm, were the primary contributors to increased HPVs. Initial results indicate that the warmest rocks are Permian and Precambrian, which is consistent with earlier results from granitoid bodies underlying the Atlantic Coastal Plain of Virginia (Speer et al., 1979). Additional bedrock samples will be analyzed to further characterize geochemical variations and potential HPVs of target rock units. Direct thermal conductivity measurements are being made of select bedrock samples in addition to sedimentary rocks of the Hartford Basin. Theoretical thermal profiles derived from rock geochemistry will provide an estimate of heat generated at depth for geologic units of interest and assist in determining the potential for an insulating layer overlying heat producing granitoids. Direct thermal conductivity measurements of unconsolidated materials throughout CT are also being made to support the ground-source heat pump industry. All data and mapping will be accessible via the National Geothermal Data System (NGDS). %B Abstracts with Programs - Geological Society of America %I Geological Society of America (GSA) : Boulder, CO, United States %C United States %V 44 %P 77 - 77 %8 2012/02/01/ %@ 00167592 %G eng %U https://gsa.confex.com/gsa/2012NE/finalprogram/abstract_200494.htm %N 22 %! Abstracts with Programs - Geological Society of America %0 Conference Proceedings %B Abstracts with Programs - Geological Society of America %D 2012 %T Implications for non-traditional geothermal resources in southern New England; variability in heat potential based on thermal conductivity and geochemistry studies %A Koteas, G. Christopher %A John Michael Rhodes %A Stephen B Mabee %A Ryan, Amy %A Schmidt, Joe %A League, Corey %A Goodhue, Nathaniel %A Adams, Sharon A. %A Gagnon, Teresa K. %A Thomas, Margaret A. %K #StaffPubs %K chemical composition %K Connecticut %K Economic geology, geology of energy sources 29A %K energy sources %K geothermal energy %K geothermal exploration %K granites %K heat flow %K igneous rocks %K massachusetts %K models %K New England %K plutonic rocks %K thermal conductivity %K United States %X Estimating geothermal potential in southern New England in the absence of borehole heat flow data or geophysical studies has led to a focus on models based on thermal conductivity, geochemistry, and density-based heat production models. Preliminary estimates of geothermal potential generally match borehole-based heat flow data from similar tectonic environments. Nevertheless, microstructural and compositional heterogeneity with depth remain largely unconstrained. The extrapolation of regional structures based on detailed field mapping has helped to improve structural projections adjacent to major basins. However, an additional source of error in models of heat potential-with-depth are thermal conductivity estimates of igneous and meta-igneous rocks throughout Massachusetts (MA) and Connecticut (CT). Over three hundred granitoid localities in MA and CT have been analyzed to date. The southern New England region can be simplified into four major litho-tectonic zones: the Taconic-Berkshire Zone of western MA and northwestern CT, The Bronson Hill Zone associated with the CT River valley, the Nashoba Zone of central MA and eastern CT, and the Milford-Dedham Zone of eastern MA and eastern CT. Granitic rocks adjacent to the CT River valley and the Narragansett Basin vary considerably in thermal conductivity. Granites adjacent to the Narragansett Basin vary from 2.9 to 3.7 W/m * K. Average thermal conductivity values, combined with modeled heat production values, produce temperatures at 3 km depth along the Narragansett Basin that approach 85-115 degrees C. Values of meta-igneous rocks from the margin of the CT River valley in MA and CT vary more considerably in thermal conductivity, from 1.8 to 3.9W/m * K. Modeled heat potentials at 3 km depths along the eastern margin of the CT River valley vary between 74-122 degrees C and appear to be largely related to compositional variation. However, local rock composition is also related to metamorphic grade and fabric development, suggesting that both fabric and composition are first order controls on thermal conductivity. Modeling based on these data set to date suggests that combining thermal conductivity, whole rock geochemistry data, and density measurements can produce accurate reconnaissance estimates of geothermal potential in southern New England. %B Abstracts with Programs - Geological Society of America %I Geological Society of America (GSA) : Boulder, CO, United States %C United States %V 44 %P 76 - 77 %8 2012/02/01/ %@ 00167592 %G eng %U https://gsa.confex.com/gsa/2012NE/finalprogram/abstract_200837.htm %N 22 %! Abstracts with Programs - Geological Society of America %0 Conference Proceedings %B Geological Society of America Abstracts with Programs %D 2013 %T Improving seismic hazard assessment in New England through the use of surficial geologic maps and expert analysis %A Becker, Laurence R. %A Patriarco, Steven P. %A Marvinney, Robert G. %A Thomas, Margaret A. %A Stephen B Mabee %A Fratto, Edward S. %K #StaffPubs %K earthquakes %K Environmental geology %K geologic hazards %K maps %K natural hazards %K New England %K risk assessment %K seismic risk %K seismic zoning %K surficial geology %K surficial geology maps %K technology %K United States %X In New England, earthquakes pose a risk to the built environment. New England state geological surveys partnered with the Northeast States Emergency Consortium to integrate geologic information and GIS analysis for risk communication. Connecticut, Maine, Massachusetts, and Vermont employed surficial geologic maps, deglaciation history, glacial stratigraphy, and professional judgment to reclassify surficial geologic materials into one of the five National Earthquake Hazard Reduction Program (NEHRP) site classifications (A, B, C, D, and E). These new classifications were used in the HAZards U.S. Multi-Hazard (HAZUS-MH) risk assessment application as a substitute for site class value of "D," used in HAZUS-MH throughout New England as a default value. Coding of surficial geologic materials for the five NEHRP site classifications was then compared with classifications using the Wald methodology, a method using 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. Geologic maps provide insights into the location of buried low shear wave velocity materials not afforded by the Wald methodology. 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 these circumstances when compared with the Wald methodology. Without the use of surficial geologic maps, significant areas of New England will be incorrectly classified as being more stable than actual site conditions would allow. By employing surficial geologic information, HAZUS-MH earthquake loss estimates are improved, providing local and regional emergency managers with more accurate information for locating and prioritizing.

%B Geological Society of America Abstracts with Programs %I Geological Society of America (GSA) : Boulder, CO, United States %C United States %V 45 %P 50 - 51 %8 2013/02/01/ %@ 00167592 %G eng %U https://gsa.confex.com/gsa/2013NE/webprogram/Paper214837.html %N 11 %! Abstracts with Programs - Geological Society of America %0 Journal Article %J Special Paper - Geological Society of America %D 2012 %T Improving seismic hazard assessment in New England through the use of surficial geologic maps and expert analysis %A Becker, Laurence R. %A Patriarco, Steven P. %A Marvinney, Robert G. %A Thomas, Margaret A. %A Stephen B Mabee %A Fratto, Edward S. %K #StaffPubs %K civil engineering %K earthquakes %K Eastern U.S. %K Engineering geology 30 %K Environmental geology 22 %K geologic hazards %K mitigation %K natural hazards %K New England %K Northeastern U.S. %K risk assessment %K risk management %K safety %K seismic risk %K seismicity %K United States %X (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. %B Special Paper - Geological Society of America %I Geological Society of America (GSA) : Boulder, CO, United States %C United States %V 493 %P 221 - 242 %8 2012/01/01/ %@ 007210779780813724935 %G eng %U http://specialpapers.gsapubs.org/content/493/221.abstract %! Special Paper - Geological Society of America