My primary research interests lie in the application of trace elemental and isotope geochemistry to time and track processes in Earth Surface and Deep Earth environments. We do not discriminate these applications based on temperature windows found in the Earth System. In addition to studying how elements and isotopes cycle through the Earth system, we also have projects collaboratively with faculty in other disciplines. For example with Archaeologists we are using these techniques to address important questions reconstructing societal dynamics of earlier civilizations and the interactions of earlier populations with their hosting environment. With microbiologists and ecologists we are working to understand linkages between geochemical and environmental positions and community dynamics.
Here are several ongoing projects that fit under this large umbrella (listed along a quasi-increasing temperature gradient):
mercury dynamics in thawing Arctic and changing temperate wetlands
wet and dry deposition of trace metals in New England
applications of isotopic systems and trace metals for sediment provenance
controls on arsenic in New England groundwater drinking supplies
geochemical cycling of calcium and magnesium in biological materials
hydrothermal vent chemistry
linking volatile history with magma genesis in extensional environments
geochemical signatures in xenoliths to reconstruct past mantle dynamics
basaltic melts as probes to the chemical structure of the mantle
The geochemistry group uses the UNH Clean lab, a ~ 1300 ft2 (~120m2) space in James Hall outfitted with minimal exposed metal, Class 10,000 general spaces and Class 1,000 workstations. The clean lab is designed with nested rooms allowing for physical as well as air supply separation of different applications subject to contamination from other procedures.
Our instrumentation is housed in the UNH plasma lab and includes a Nu instruments attoM high resolution single-collector inductively coupled plasma mass spectrometer and a Nu plasma II-ES multicollector inductively coupled plasma mass spectrometer. For sample introduction, the plasma geochemistry lab also includes two lasers (a 193 nm photon machines Excite excimer laser and a New Wave 213 nm deep UV laser), desolvating nebulizers and two hydride generators + cold vapor introduction systems (one typically dated for hydride generation for arsenic applications and a second typically run in cold vapor for mercury analyses). A Milestone direct mercury analysis instrument is available for mercury analysis via thermal decomposition.
Both the UNH Clean lab and the UNH plasma lab include exhausting polypropylene laminar flow hoods, polypropylene laminar flow workstations, centrifuges, balances, ultrasonicating mixers, water polisher systems capable of achieving 18MO•cm DI water and Teflon-coated hot plates. Our in situ work is supported by petrographic microscopes, ‘picking’ scopes with variable zoom ranges and rock preparation facilities available through the Department of Earth Sciences.
We are happy to welcome collaborative or contract studies into our geochemical laboratories. For additional information, discussion of applications including our approved billing rates, please contact me.
Associate Editor, G-cubed.
Technical Reviewer (many journals; NSF, USGS proposals) and Review Panel member (NSF)
Geochemical Society – Clarke Committee Member (2009-2011, Chair 2011) + Technical Program Organizer (Theme member, Goldschmidt 2011; Theme leader, Goldschmidt 2013)
UNH service- Department Chair (2012-2018, with sabbatical 2016-2017) and associated membership of the College of Engineering and Physical Sciences Executive Committee; Undergraduate Coordinator (2018 - ); Faculty Fellow in the Office of the Senior Vice Provost for Engagement and Faculty Development
Ph.D., Geological Sciences, University of California - Santa Barbara
B.A., Environmental Sciences, University of Virginia
ESCI 401: Dynamic Earth
ESCI 420: Our Solar System
ESCI 451: Earth in Film
ESCI 741/841: Geochemistry
ESCI 745/845: Isotope Geochemistry
ESCI 766/866: Volcanology
INCO 590: Rsrch Exp/Earth Sciences
INCO 790: Adv Rsrch Exp/Earth Sciences
Louati, M., Ennis, N. J., Ghodhbane‐Gtari, F., Hezbri, K., Sevigny, J. L., Fahnestock, M. F., . . . Gtari, M. (2020). Elucidating the ecological networks in stone‐dwelling microbiomes. Environmental Microbiology, 22(4), 1467-1480. doi:10.1111/1462-2920.14700
Perryman, C. R., McCalley, C. K., Malhotra, A., Fahnestock, M. F., Kashi, N. N., Bryce, J. G., . . . Varner, R. K. (2020). Thaw Transitions and Redox Conditions Drive Methane Oxidation in a Permafrost Peatland. Journal of Geophysical Research: Biogeosciences, 125(3). doi:10.1029/2019jg005526
Fahnestock, M. F., Bryce, J. G., McCalley, C. K., Montesdeoca, M., Bai, S., Li, Y., . . . Varner, R. K. (2019). Mercury reallocation in thawing subarctic peatlands. Geochemical Perspectives Letters, 33-38. doi:10.7185/geochemlet.1922
Marchina, C., Natali, C., Fahnestock, M. F., Pennisi, M., Bryce, J., & Bianchini, G. (2018). Strontium isotopic composition of the Po river dissolved load: Insights into rock weathering in Northern Italy. Applied Geochemistry, 97, 187-196. doi:10.1016/j.apgeochem.2018.08.024
Phillips, S. C., Hong, W. -L., Johnson, J. E., Fahnestock, M. F., & Bryce, J. G. (2018). Authigenic carbonate formation influenced by freshwater inputs and methanogenesis in coal-bearing strata offshore Shimokita, Japan (IODP site C0020). Marine and Petroleum Geology, 96, 288-303. doi:10.1016/j.marpetgeo.2018.06.007
Furman, T., Kaleta, K. M., Bryce, J. G., & Hanan, B. B. (2006). Tertiary mafic lavas of Turkana, Kenya: Constraints on East African plume structure and the occurrence of high-mu volcanism in Africa. JOURNAL OF PETROLOGY, 47(6), 1221-1244. doi:10.1093/petrology/egl009
Furman, T., Bryce, J., Rooney, T., Hanan, B., Yirgu, G., & Ayalew, D. (2006). Heads and tails: 30 million years of the Afar plume. Geological Society, London, Special Publications, 259(1), 95-119. doi:10.1144/gsl.sp.2006.259.01.09
Bryce, J. G., DePaolo, D. J., & Lassiter, J. C. (2005). Geochemical structure of the Hawaiian plume: Sr, Nd, and Os isotopes in the 2.8 km HSDP-2 section of Mauna Kea volcano. Geochemistry, Geophysics, Geosystems, 6(9), n/a. doi:10.1029/2004gc000809
Furman, T., Bryce, J. G., Karson, J., & Iotti, A. (2004). East African Rift System (EARS) plume structure: Insights from quaternary mafic lavas of Turkana, Kenya. JOURNAL OF PETROLOGY, 45(5), 1069-1088. doi:10.1093/petrology/egh004
DePaolo, D. J., Bryce, J. G., Dodson, A., Shuster, D. L., & Kennedy, B. M. (2001). Isotopic evolution of Mauna Loa and the chemical structure of the Hawaiian plume. GEOCHEMISTRY GEOPHYSICS GEOSYSTEMS, 2. Retrieved from http://gateway.webofknowledge.com/