@proceedings {280, title = {Deep geothermal potential of New England granitoids; the Fall River Pluton, southeastern Massachusetts}, volume = {43}, year = {2011}, note = {Accession Number: 2012-031359; Conference Name: Geological Society of America, Northeastern Section, 46th annual meeting; Geological Society of America, North-Central Section, 45th annual meeting; Pittsburgh, PA, United States; Conference Date: 20110320; Language: English; Coden: GAAPBC; Collation: 1; Collation: 63; Publication Types: Abstract Only; Serial; Conference document; Updated Code: 201217; Monograph Title: Geological Society of America, Northeastern Section, 46th annual meeting; Geological Society of America, North-Central Section, 45th annual meeting; Monograph Author(s): Anonymous; Reviewed Item: Analytic}, month = {2011/03/01/}, pages = {63 - 63}, publisher = {Geological Society of America (GSA) : Boulder, CO, United States}, address = {United States}, abstract = {Devonian-aged plutonic rocks that are interpreted to be part of the Fall River pluton, along the southern edge of the Narragansett Basin, appear to have potential as a source of deep geothermal energy. The Narragansett Basin covers a approximately 1500 Km (super 2) area in southern Massachusetts and is dominated by complexly deformed and metamorphosed, Pennsylvanian-aged, fluvial and alluvial deposits. A northeast-striking series of brittle faults and discrete shear zones define the southern margin of the basin. Preliminary modeling of igneous and gneissic fabrics from outcrops along the southern edge of the basin show that the granite dips predominantly north, northeast. This pattern suggests that granitoids along the southern edge of the basin continue beneath the Narragansett Basin and correlate with granitoids exposed to the north. Regional joint sets in the Fall River pluton can be grouped into three dominant clusters at 350 degrees , 90 degrees , and 250 degrees based upon 86 field measurements. Low-angle sheeting joints are also common and suggest interconnected fracture networks at depth. Preliminary geochemistry from the Fall River pluton suggests that feldspars and accessory minerals contain the appropriate concentrations of heat producing elements, primarily U, Th, and K, to be a reasonable geothermal resource. K (sub 2) O values range from 2.4 to 5.0 weight percent. U and Th values (in ppm) range from 0.9 to 6.2 and 2.9 to 30.1 respectively. Assuming a relatively consistent composition at depth, a density of 2.6 kg/m (super 3) , and a thermal conductivity of 2.9 W/m degrees C, initial temperature modeling suggests average temperatures of 81 degrees C at depths of 5 kilometers and 93 degrees C at depths of 6 kilometers. Temperature estimates increase to approximately 150 degrees C and approximately 170 degrees C respectively when a two kilometer thick sediment package is modeled overlying the granitoids. The goal of current and future work is to improve assumptions about compositional uniformity as well as the regional position of granitoids at depth. At the conclusion of this work we hope to develop a protocol for studying geothermal potential of buried granitoids in New England in the absence of reliable drill-hole data. Preliminary estimates from this project suggest that basins underlain by granitoids of compositions similar to that of the Fall River pluton have reasonable potential as a deep geothermal resource.}, keywords = {$\#$StaffPubs, depth, Economic geology, geology of energy sources 29A, Fall River Pluton, geochemistry, geothermal energy, gneisses, granites, Igneous and metamorphic petrology 05A, igneous rocks, intrusions, massachusetts, metamorphic rocks, plutonic rocks, plutons, southeastern Massachusetts, United States}, isbn = {00167592}, url = {https://gsa.confex.com/gsa/2011NE/finalprogram/abstract_185900.htm}, author = {Goodhue, Nathaniel and Koteas, G. Christopher and John Michael Rhodes and Stephen B Mabee} }