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Gary Hemming

Associate Professor
Geochemistry

Science Building, Room E224
Phone: 718-997-3335
hemming@qc.edu



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Research Interests

Boron Isotopes: Our major research initiative is an NSF funded study to ground-truth the boron isotope paleo-pH proxy. Boron isotopes in marine carbonates have the potential to provide us with information about past ocean chemistry, as the boron isotopic composition of marine carbonates is primarily controlled by the ocean’s carbonate chemistry. The core of the study is a test of the boron isotope paleo-pH proxy by a global survey of core-top planktonic and benthic foraminifera from sites where water chemistry has been well-characterized. This will give the opportunity to evaluate deviations from predicted isotope compositions resulting from controls other than pH, such as species effects, temperature, and alkalinity. Concurrent with this survey are laboratory experiments and foraminifera culture experiments where potential variables can be tightly controlled, as well as a test of one aspect of diagenesis, sediment dissolution. We will apply this knowledge to studies of paleo-ocean chemistry and paleo-climate studies.

Radiogenic Isotopes for Solid Earth, Hydrogeochemical, Paleoclimate, and Environmental studies: Radiogenic isotope studies are widely used in the Earth Sciences for solid earth, hydrology/environmental, and paleoclimate applications. Our work includes Pb isotope studies of lake sediments in the New York City area (in collaboration with Steve Chillrud of the Lamont-Doherty Earth Observatory), Pb isotopes as a tracer for the bio-availability of Pb contaminated soil (Chillrud et al., 2004; Hemming et al., 2003), and Pb isotope studies to trace sources and thus trade routes based on South American artifacts (with the Metropolitan Museum’s Ellen Howe). We use Sr isotopes as chemostratigraphic (e.g., Rasbury et al., in press), hydrological (Pedone et al., 2000; Pedone et al., 2002a; Tomascak et al., 2003), paleohydrological/paleoclimate (Pedone et al., 2002b, Zimmerman et al., 2002), and terrigenous sediment tracers (Hemming et al., 1998; Cullen et al., 2000).



Publications

Chillrud, S.N., Hemming, N.G., Ross, J., Wallace, S.M., and LoIancono, N., 2003, A rapid and precise procedure for Pb isotopes in whole blood by Fe co-precipitation and MC-ICPMS analysis, Applied Geochemistry (in review).

Tomascak P.B., Hemming N.G., and Hemming S.R., 2003, The lithium isotopic composition of waters of the Mono Basin, California. Geochim. Cosmochim. Acta (in press)

Reynaud, S., Hemming, N.G., Juillet-Leclerc , A., and Gattuso, J-P, 2003, Effect of pCO2 and temperature on the boron isotopic composition of a zooxanthellate coral: Acropora sp., Coral Reef, Special Volume on Environmental and Climatic Proxies in Reef Organisms, (in press).

Rasbury, E.T., Ward, W.B., Hemming, N.G., Li, H., Dickson, J.A.D., Hanson, G.N.,. and Major, R.P., 2003, Timing the Deposition of the Late Carboniferous Laborcita Formation, New Mexico, USA by U-Pb Dating and 87Sr/86Sr of Marine Cements. Earth and Planetary Science Letters, (in press).

Hönisch, B., Hemming, N.G., Grottoli, A.G., Amat, A., Hanson, G.N., and Bijma, J., 2003, Assessing scleractinian corals as recorders for paleo-pH: Empirical calibration and vital effects, Geochim. Cosmochim. Acta (accepted for publication).

Cullen, Heidi, deMenocal, P.B., Hemming, S.R., Hemming, N.G, Brown, F.H., Guilderson, T., and Sirocko, F., 2000, Climate change and the collapse of the Akkadian empire: Evidence from the deep sea, Geology, V. 28, p. 379-382.

Hemming, N.G., Reeder, R.J., and Hart, S.R., 1998, Growth-step selective incorporation of boron on the calcite surface, Geochimica et Cosmochimica Acta, V. 62, p. 2915-2922.

Hemming, N.G., Guilderson, T.P., and Fairbanks, R.H., 1998, Seasonal variations in the boron isotopic composition of coral: A productivity signal?, Global Biogeochemical Cycles, V. 12, p. 581-586.

Hemming, S.R., Biscaye, P.E., Broecker, W.S., Hemming, N.G., Klas, M., and Hajdas, I., 1998, Provenance change coupled with increased clay flux during deglacial times in the Western Equatorial Atlantic, Palaeogeography, Palaeoclimatology, Palaeoecology, V. 142, p. 217-230.

Sanyal, A., Hemming, N.G., and Broecker, W.S, 1997, Changes in pH in the eastern equatorial Pacific across stage 5-6 boundary based on boron isotopes in foraminifera, Global Biogeochemical Cycles, V. 11, p. 125-133.

Sanyal, A., Hemming, N.G., Broecker, W.S., Lea, David W., Spero, Howard J., and Hanson, G.N., 1996, Oceanic pH control on the boron isotopic composition of foraminifera: Evidence from culture experiments, Paleoceanography V. 11, p. 513-517.

Sanyal, A., Hemming, N.G., Hanson, G.N., and Broecker, W.S., 1995, The pH of the glacial ocean as reconstructed from boron isotope measurements on foraminifera, Nature, V. 373, p. 234-236.

Hemming, N.G., Reeder, R.J., and Hanson, G.N., 1995, Mineral/fluid partitioning and isotopic fractionation of boron in synthetic calcium carbonate, Geochimica et Cosmochimica Acta, V. 59, p. 371-379.

Hemming, N.G. and Hanson, G.N., 1994, A procedure for the analysis of boron by negative thermal ionization mass spectrometry, Chemical Geology, V. 114, p. 147-156.

Sen, S., Stebbins, J.F., Hemming, N.G., and Ghosh, B., 1994, Coordination environments of boron impurities in calcite and aragonite polymorphs: A 11B MAS NMR study, American Mineralogist, V. 79, p. 819-825.

Hemming, N.GHemming, N.G. and Hanson, G.N., 1992, Boron isotopic composition and concentration in modern marine carbonates, Geochimica et Cosmochimica Acta, V. 56, p. 537-543. G., Meyers, W.J., and Grams, J.C., 1989, Cathodoluminescence in diagenetic calcites: the roles of Fe and Mn as deduced from electron probe and spectrophotometric measurements, Journal of Sedimentary Petrology, V. 59, 3, p. 404-411.

Selected Abstracts:

Krogstad, E.J., Bizzarro, M., and Hemming, N.G., 2003, Mg isotopic compositions of modern marine carbonates, American Geophysical Union, 2003 Fall Meeting, San Francisco, CA, Abstracts with Programs.

Hönisch, B. and Hemming, N.G., 2003, Ground-truthing the boron isotope paleo-pH proxy in planktonic foraminifera shells: Partial dissolution and shell size effects, American Geophysical Union, 2003 Fall Meeting, San Francisco, CA, Abstracts with Programs.

Hemming, N.G., Ross, J.M., Wallace, S., LoIacono, N., and Chillrud, S.N., 2003, A rapid and precise procedure for Pb isotopes in whole blood by Fe co-precipitation and MC-ICPMS analysis, 5th International Symposium on Applied Isotope Geochemistry, International Association of Geochemistry and Cosmochemistry, Program and Abstracts, p. 29.

Pedone, V.A., Hemming, N.G., Quade, J., and Kaufman, D.S., 2000, Inverse covariance between lake volume and strontium isotopic composition in the Great Salt Lake, Utah: Geological Society of America Abstracts with Programs, v. 32.

Zimmerman, S.R.H., Hemming, S.R., Hemming, N.G., and Tomascak, P.B., 2002, Late Pleistocene variations of lake level and glacial activity at Mono Lake, CA, USA, VM Goldschmidt Conference, Davos, Switzerland.

Hönisch, B.; Hemming, N.G.; Grottoli, A.G.; Amat, A.; Hanson, G.N.; Bijma, J., 2003, The effect of light, respiration and pCO2 on d11B in coral skeletons: results from culture and field experiments, EGS - AGU - EUG Joint Assembly, Nice, France, Abstracts with Program.

Chillrud, S.N., Wallace, S.M., Hemming, N.G., and Ross, J., 2002, Determination of lead isotopes in blood using FeOH co-precipitaion separation method and analysis by multi-collector ICPMS, 2002 Winter Conference on Plasma Spectrochemistry, Scottsdale, AZ, Abstracts with Program.

Pedone, V. Hemming, N.G., and Olson, J., 2002, Geochemical and Mineralogical Records from Ancient Lake Sediments, Geol. Soc. of Am. Annual Meeting, Denver, CO, Abstracts with Program.

Pedone, V., Hemming, N.G., and Oson, J., 2002, Definition of the hydrogeologic history of the transgressive phase of Lake Bonneville, Utah by Sr isotopes, Geol. Soc. of Am. Annual Meeting, Denver, CO, Abstracts with Program.

Tomascak P.B., Hemming N.G., and Hemming S.R., 2001, Controls on lithium isotope fractionation in evaporite systems. GSA Abst Prog

Tomascak P.B., Hemming N.G., and Hemming S.R., 2001, Lithium isotopes in the Mono basin hydrologic system, Mono Lake, CA. Extended Abstract, Applied Isotope Geochemistry IV, Asilomar, CA.

Tomascak P.B., Hemming N.G., and Pedone V.A. , 2001, Lithium, boron, and strontium isotope constraints on solute sources for the Great Salt Lake, Utah. Eleventh V.M. Goldschmidt Conference Abst.

Tomascak P.B., Hemming N.G., and Hemming S.R., 2000, Coupled Li-Sr isotope variations in the Mono Lake hydrologic system. Geol. Soc. Amer. Abst.

Hemming, N.G., and Swart, P.K., 2001, Boron isotope compositions of sediment interstitial brines, ODP Leg 182, Great Australian Bight, American Geophysical Union, Abstracts with Programs, V. 82.

Hemming, N.G., and Goldstein, S.L., 2001, Analytical procedures for the high precision analysis of boron isotopes in carbonates and natural waters on the Axiom multi-collector ICPMS, Applied Isotope Geochemistry 4, Asilomar, CA.

Tomascak, P.B., Hemming, N.G., Pedone, V.A., 2001, Lithium, boron, and strontium isotope constraints on solute sources for the Great Salt Lake, Utah, Eleventh Annual V.M. Goldschmidt Conference, Hot Springs, VA, Abstracts, on C.D.

Tomascak P.B., Hemming N.G., and Hemming S.R.,1999, Lithium isotope geochemistry of Mono Lake, California. Seventh International Conf. on Salt Lakes, Furnace Creek, CA.

Tomascak P.B., Hemming N.G., and Hemming S.R., 1999, Lithium isotope geochemistry of Mono Lake, California. In: Ninth Annual V.M. Goldschmidt Conf., L.P.I. Contribution 971, p. 301, Lunar and Planetary Institute, Houston.

Hemming, N.G., 1999, Brachiopods as an archive of the secular variation of boron isotopes in seawater, American Geophysical Union, Abstracts with Programs, V. 80, p. F545.

Hemming, N.G., Goldstein, S.L., and Fairbanks, R.G., 1999, Osmium isotopic analysis by dynamic multiple collector inductively coupled plasma mass spectrometer using iridium-191 signal normalization, Ninth Annual V.M. Goldschmidt Conference, Cambridge, MA, Abstracts, p. 120.

Cullen, Heidi, deMenocal, P., Hemming, S.R., Hemming, N.G, Brown, F., 1997, Possible role of climate in the collapse of the Akkadian Empire: evidence from Gulf of Oman marine sediments, American Geophysical Union, Abstracts with Programs, V. 78, p. F376.

Hemming, N.G., Guilderson , T.P., Fairbanks, R.G., 1998, Coupled Seasonal Variation in the boron and carbon isotope composition of coral, American Geophysical Union, Abstracts with Programs, V. 78, p. F388.

Sanyal, A., Hemming, N.G., and Hanson, G.N., 1997, Changes in pH in the eastern equatorial Pacific across stage 5-6 boundary based on boron isotopes in foraminifera, American Geophysical Union, Abstracts with Programs, V. 77, p. F297.

Hemming, N.G., Liu, T., and Broecker, W.S., 1997, Constraints on desert varnish provenance using radiogenic isotope signatures, 1997 V.M. Goldschmidt Conference, Tucson, Arizona, p. 91-92.

Barth, Susanne, Hemming, N.G., Hanson, G.N., Hoehn, E., and Gercken, B., 1996, Boron isotope systematics in ground waters from solid waste disposal sites (Switzerland): A new tracer for anthropogenic contamination, 1996 V. M. Goldschmidt Conference, Heidleberg, Germany.

Hemming, N.G., Guilderson, T.P., Sanyal, A., Broecker, W.S., and Fairbanks, R.H., 1996, Boron isotopes in carbonates as a proxy for paleo-pH: Applications and limitations, 1996 V. M. Goldschmidt Conference, Heidleberg, Germany.

Hemming, N.G., Guilderson, T.P., Sanyal, A., Broecker, W.S., and Fairbanks, R.H., 1995, Boron isotope variation within single coral samples, American Geophysical Union, Abstracts with Programs, V. 76, p. F319.

Sanyal, A., Hemming, N.G., Lea, D.W., Spero, H.J., and Broecker, W.S., 1995, Oceanic pH control on the boron isotopic composition of foraminifera: evidence from culture experiments, American Geophysical Union, Abstracts with Programs, V. 76, p. F321.

Hemming, N.G., Sanyal, A., Broecker, W.S., Guilderson, T.P., Rubenstone, J.L., and Fairbanks, R.H., 1995, Boron isotopic composition of Holocene and Pleistocene coral from Barbados, European Union of Geosciences, Abstracts with Programs.

Hemming, N.G., Reeder, R.J., and Hanson, G.N., 1995, Boron isotope partitioning in natural and synthetic calcium carbonates, V.M. Goldschmidt Conference, Abstracts with Programs.

Sanyal, A., Hemming, N.G., Hanson, G.N., and Broecker, W.S., 1995, pH estimation of glacial oceans based on boron isotopic composition of foraminifera, ICOG-8, Berkeley, CA.

Hemming, N.G., Hanson, G.N., and Meyers, W.J., 1993, Host rock control on the boron concentration and isotopic composition of ground water from the Edwards Aquifer of Central Texas, American Association of Petroleum Geologists Abstracts with Programs, 1993 Annual Convention, p. 116-117.

Sanyal, A., and Hemming, N.G., 1993, Boron isotopic composition of foraminifera as a potential pH indicator, American Geophysical Union Fall Meeting, V. 74.

Hemming, N.G., Hanson, G.N., and Meyers, W.J., 1991, Boron isotopic composition of Osagean (Miss.) marine cements and brachiopods: implications for marine cement fluids and secular variation of B isotopes, Geological Society of America Abstracts with Programs, V. 23, 5, p. A149.

 
 

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