TY - Generic T1 - Geochemistry of gneisses and amphibolites in the Uchee Belt of western Georgia and eastern Alabama; an ACRES progress report T2 - Abstracts with Programs - Geological Society of America Y1 - 2000 A1 - Joseph P Kopera A1 - Nicholas, Brian A1 - Todd, Dave A1 - Davison, Jeff A1 - Hanley, Tom A1 - Kar, Aditya A1 - La Tour, Timothy E. A1 - Edwards, Tonya KW - #StaffPubs KW - Alabama KW - amphibolite KW - chemical composition KW - Columbus Georgia KW - dikes KW - Georgia KW - gneisses KW - Igneous and metamorphic petrology 05A KW - inclusions KW - intrusions KW - metamorphic rocks KW - Muscogee County Georgia KW - Uchee Belt KW - United States KW - xenoliths AB - Undergraduate students, high school teachers, and university faculty representing ACRES (Atlanta Consortium for Research in Earth Sciences) studied lineated gneiss (LG) exposed at Flat Rock Park (FRP) and vicinity in Columbus, GA, and Motts gneiss (MG) in eastern Alabama. The LG and MG are mineralogically and geochemically granitoidal lineated orthogneisses. They contain deformed mafic xenoliths, as well as aplitic, granitic and pegmatoidal dikes that cut the dominant lineation. Based on chemical analyses, the LG from FRP and the MG plot as granite on the IUGS diagrams and the Le Bas diagram. Similarity in incompatible trace element ratios (e.g., Zr/Nb) and highly evolved characteristics of aplite with respect to the host gneisses, indicate there is probably a genetic link between the MG and the FRP LG. These rocks are chemically distinct from other nearby felsic gneiss. Phenix City gneiss amphibolites from Lindsey Creek and North Highland Mills dam in Columbus were also analyzed for major and trace elements. These amphibolites are low K tholeiitic rocks with an island arc affinity and are similar to rocks from the area that have already been analyzed. The amphibolites show a wide range of fractionation (41 to 62 percent SiO (sub 2) ). Consistency in incompatible element ratios over a wide range of fractionation of some of the samples show a probable genetic relationship among the various amphibolites of Lindsey Creek. Future work should involve more extensive collecting and analysis of both felsic rocks and amphibolites in the Uchee belt. More time should also be spent describing the thin sections of the existing collection and comparing the REE patterns for the FRP, MG and other felsic rocks in the Uchee belt. JF - Abstracts with Programs - Geological Society of America PB - Geological Society of America (GSA) : Boulder, CO, United States CY - United States VL - 32 SN - 00167592 IS - 22 N1 - Accession Number: 2002-039126; Conference Name: Geological Society of America, Southeastern Section, 49th annual meeting; Charleston, SC, United States; Conference Date: 20000323; Language: English; Coordinates: N322800N322800W0845900W0845900; Coden: GAAPBC; Collation: 1; Collation: 31; Publication Types: Abstract Only; Serial; Conference document; Updated Code: 200214; Monograph Title: Geological Society of America, Southeastern Section, 49th annual meeting; Monograph Author(s): Anonymous; Reviewed Item: Analytic JO - Abstracts with Programs - Geological Society of America ER - TY - Generic T1 - Implications for non-traditional geothermal resources in southern New England; variability in heat potential based on thermal conductivity and geochemistry studies T2 - Abstracts with Programs - Geological Society of America Y1 - 2012 A1 - Koteas, G. Christopher A1 - John Michael Rhodes A1 - Stephen B Mabee A1 - Ryan, Amy A1 - Schmidt, Joe A1 - League, Corey A1 - Goodhue, Nathaniel A1 - Adams, Sharon A. A1 - Gagnon, Teresa K. A1 - Thomas, Margaret A. KW - #StaffPubs KW - chemical composition KW - Connecticut KW - Economic geology, geology of energy sources 29A KW - energy sources KW - geothermal energy KW - geothermal exploration KW - granites KW - heat flow KW - igneous rocks KW - massachusetts KW - models KW - New England KW - plutonic rocks KW - thermal conductivity KW - United States AB - 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. 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_200837.htm IS - 22 N1 - Accession Number: 2012-090079; Conference Name: Geological Society of America, Northeastern Section, 47th annual meeting; Hartford, CT, United States; Conference Date: 20120318; Language: English; Coordinates: N420000N473000W0670000W0733000; Coden: GAAPBC; Collation: 2; Collation: 76-77; 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 -