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2019 Birdsall-Dreiss                                  1.  Chasing Helium: Mantle-to-Surface Connections to Water
                                                                  Quality and Geomicrobiology. The discovery of oceanic
          Distinguished Lecturer                                  black (and white) smokers revolutionized our understanding of
                                                                  mid-ocean ridges and led to the recognition of new organisms
                                                                  and ecosystems resulting from mixing of fluids. Continental
                                                                  smokers, defined here to include a broad range of carbonic
                                                                  springs, hot springs, and fumaroles that vent mantle-derived
                              Laura J. Crossey is a professor in the   fluids in continental settings, exhibit many of the same
                            Dept. of Earth & Planetary Sciences at the   processes of heat and mass transfer and ecosystem niche
                            University of New Mexico (UNM). She   differentiation. The application of noble gas geochemistry
                            received her bachelor’s degree in geology at   (specifically helium isotope [ He/ He] analyses) indicates
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                            Colorado College (1977), master’s degree at   widespread mantle degassing in perhaps unexpected tectonic
                            Washington University in St. Louis (1979),   locales including the western U.S., the Great Artesian basin
                            and Ph.D. from the University of Wyoming   of Australia, the Western Desert of Egypt, and the Tibetan
                            (1985). She joined the UNM faculty in 1986   Plateau. Variations in the mantle helium component measured
                            and was the first woman in the department   in groundwaters correlate best with low seismic-velocity
          Laura J. Crossey  to be tenured, promoted to full professor,   domains in the upper mantle and with abrupt lateral contrasts
                            and serve as chair.                   in mantle velocity rather than crustal parameters such as strain
                                                                  rate, proximity to volcanoes, crustal velocity, or composition.
            Crossey’s research group explores applications of low-temper-  Microbial community analyses applied to several of these
          ature geochemistry to problems in hydrochemistry, diagenesis,   areas indicate that these springs can host novel micro-
          geomicrobiology, and geothermal processes. Her approach    organisms. Our work yielded the first published occurrence
          combines field examination of modern laboratory analysis as   of chemolithoautotrophic Zetaproteobacteria in a continental
          well as core and outcrop study to evaluate paleohydrology,   setting. These observations led to two linked hypotheses.
          spring sustainability, and reservoir/aquifer characteristics.   (1) Mantle-derived volatiles transit through conduits in extend-
          Related activities include geoscience outreach, K–12 outreach,   ing continental lithosphere preferentially above and at the
          science education research, and programs to increase the    edges of mantle low-velocity domains. (2) Elevated concentra-
          participation of underrepresented groups in science. She is    tions of CO  and other constituents ultimately derived from
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          a leader on the National Science Foundation–funded New   mantle volatiles drive water-rock interactions and heteroge-
          Mexico Alliance for Minority Participation Award and has   neous fluid mixing that help structure diverse and distinctive
          served on numerous review panels and volunteer boards.   microbial communities. This recognition of the small volume
                                                                  but chemically potent “lower world” contributions to ground-
            A GSA member since 1997 and Fellow since 2012, Crossey   water systems has implications for topics as diverse as tecton-
          has served as president of the Sedimentary Geology Division,   ics, fluid conduits, water quality, and microbial ecosystems.
          Technical Program Chair for the Rocky Mountain Section,
          associate editor for GSA Bulletin, Geochimica et Cosmochimica   2.  Hydrochemistry and Geoscience Education at Grand
          Acta, and Applied Geochemistry, and was editor of SEPM   Canyon and Beyond: Who Knew Groundwater Hydrology
          (Society for Sedimentary Geology) Special Publications.    Could Be So Complicated? Springs and associated riparian
          She was awarded lifetime membership in the New Mexico   environments provide critical habitats for aquatic and
          Geological Society. She and her husband, Karl Karlstrom, were   terrestrial wildlife in the Grand Canyon region and drinking
          awarded an Outstanding Achievement Award by the American   water for Grand Canyon National Park. Grand Canyon springs
          Institute of Professional Geologists in 2015 for designing and   are fed by world-class karst aquifer systems on the Colorado
          building the Trail of Time, a geoscience exhibition at the Grand   Plateau, but increasing pressure on groundwater resources
          Canyon (funded by the National Science Foundation, and recog-  from climate change, mining, and other development poses
          nized as Best Wayside Exhibit by the National Association for   major challenges to resource managers. The shallow and deep
          Interpretation in 2011).                                karst systems of the region interact in ways that are revealed
                                                                  by recent studies. General hydrologic models for the Colorado
            Crossey’s research on carbonic springs has taken her to the   Plateau aquifers highlight the importance of recharge areas
          Great Artesian basin of Australia, the Western Desert of Egypt,   (“springsheds”) for water supply. Ongoing work helps explain
          and the Tibetan Plateau.                                these complex relationships using multiple tracer methods.
                                                                  A robust monitoring and geochemical sampling program
            Institutions can schedule a lecture on one of the topics   provides data for understanding the sustainability of spring-
          described below at community.geosociety.org/hydrodivision/  fed water supplies for anthropogenic use. Geochemical studies
          birdsall/about2019. (Crossey is also happy to present brown   of spring waters (including dissolved gases) have identified
          bags or visit with faculty, staff, and/or students on topics such as   the importance of mantle-derived volatiles and CO  that
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          inclusion and diversity in STEM.)                       contribute dissolved salts and other products of water-rock





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