Pete Barry

Pete Barry

USGS Research Fellow

The goal of my research is to understand the volatile history and chemical evolution of Earth. Specifically, I use stable and noble gas isotope systematics to understand the dynamic processes of subduction, mantle convection and surface volcanism, which control the redistribution of chemical constituents between the crust and mantle reservoirs. I am interested in addressing a diverse array of geochemical questions, pertaining to both igneous and crustal systems. My primary research focus has been on high-temperature geochemistry, crust-mantle interactions and the behavior of volatile fluids in the lithosphere.  However, my most recent research focuses on using noble gas geochemistry to better understand crustal systems, including hydrocarbon formation and transport mechanisms.

I am the lead investigator on an interdisciplinary Deep Carbon Observatory project to investigate the complex interplay between biotic and abiotic carbon in a subduction zone setting. Specifically, the goal of our expedition was to bring together early career scientists from various different fields (i.e., petrologists, geochemists, microbiologists) to study the effects of biology (either living or dead) on the budgets and isotopic compositions of carbon compounds at the Costa Rica convergent margin. We measured volatile fluxes across a broad transect of the Costa Rica margin, and in total we collected gas and fluids samples from ~30 discrete localities in the fore-arc, volcanic-arc and back-arc. We made a video about our work, which won first prize at the Goldschmidt Film Festival in Paris in August 2017:


Barry P.H., and Hilton, D.R. (2016) Release of subducted sedimentary nitrogen throughout Earth’s mantle. Geochemical Perspectives Letters, in press.

Correale, A., Rizzo, A.L., Barry, P.H., Lu, J., Zheng, J. (2016) Refertilization of lithospheric mantle beneath the Yangtze Craton, South East China: evidence from the noble gas geochemistry. Gondwana, in press. doi:10.1016/j.gca.2015.12.021.

Halldórsson, S.A., Hilton, D.R., Barry, P.H., Füri, E., Grönvold, K. (2015) Recycling of Phanerozoic crustal material by the Iceland mantle plume: new evidence from nitrogen elemental and isotope systematics of subglacial basalts. Geochim. Cosmochim. Acta, 176, 206-226. doi:10.1016/j.gca.2015.12.021

Füri, E., Barry, P.H., Taylor, L.A., Marty, B. (2015) Indigenous nitrogen in the Moon: Constraints from coupled nitrogen-noble gas analyses of mare basalts. Earth and Planetary Science Letters, 431, 195-205. doi:10.1016/j.epsl.2015.09.022.

Day, J. M. D., Barry, P. H., Hilton, D.R., Burgess, R., Pearson D.G., and Taylor, L.A. (2015) The helium flux from the continents and ubiquity of low-3He/4He recycled crust and lithosphere. Geochim. Cosmochim. Acta, 153, 116-133. doi: 10.1016/j.gca.2015.01.008.

Barry, P. H., Hilton, D. R., Day J.M.D., Pernet-Fisher, J.F., Howarth, G.H., Agashev A.M., Pokhilenko N.P., Pokhilenko L.N., and Taylor, L.A. (2015) Helium isotope evidence for modification of the cratonic lithosphere during the Permo-Triassic Siberian flood basalt event. Lithos, 216-217, 73-80. doi: 10.1016/j.lithos.2014.12.001.

Barry, P.H., Hilton, D.R., Füri, E., Halldórsson, S.A., Grönvold, K. (2014) Carbon isotope and abundance systematics, and CO2 fluxes from Icelandic geothermal gases, fluids and subglacial basalts, Geochim. Cosmochim. Acta, 134, 74-99. doi:

Howarth, G.H., Barry, P.H., Pernet-Fisher, J.F., Baziotis, I.P., Pokhilenko, N.P., Pokhilenko, L.N., Bodnar, R.J., Taylor, L.A. (2014) Superplume Metasomatism: Evidence from Siberian mantle xenoliths, Lithos, 184–187, 209–224. doi: 10.1016/j.lithos.2013.09.006

Carmody, L., Barry, P.H., Shervais J.W., Kluesner, J.W. Taylor, L.A. (2013) Oxygen Isotopes in Subducted Oceanic Crust: A New Perspective from Siberian Diamondiferous Eclogites. Geology, Geophysics, and Geosystems (G-Cubed), 14. doi: 10.1002/ggge.20220.

Barry, P.H. and Taylor, L.A. (2013) Age of the Earth. In: Rink W., Thompson J. (Ed.) Encyclopedia of Scientific Dating Methods. doi: 10.1007/978-94-007-6326-5_65-7.

Barry, P.H., Hilton, D.R., Fischer, T.P., de Moor, J.M., Mangasini, F, Ramirez, C.J., (2013) Helium and carbon isotope systematics of cold “mazuku” CO2 vents and hydrothermal gases and fluids from Rungwe Volcanic Province, southern Tanzania, Chemical Geology 339, pp 141-156. doi: 10.1016/j.chemgeo.2012.07.003.

Barry, P.H., Hilton, D.R., Halldórsson S. A., Hahm, D. and Marti, K. (2012) High precision nitrogen isotope measurements in oceanic basalts using a static triple collection noble gas mass spectrometry. Geology, Geophysics, and Geosystems (G-Cubed), (Technical Briefs) 13, Number 1. doi: 10.1029/2011GC003878, 2012.

Barry, P.H., Hilton, D.R., Tryon, M.D., Brown, K.M., and Kulongoski, J.T. (2009) A New Syringe Pump Apparatus for the Retrieval and Temporal Analysis of Helium (SPARTAH) in groundwaters and geothermal fluids, Geology, Geophysics, and Geosystems (G-Cubed), (Technical Briefs) 10, Number 5, doi: 10.1029/2009GC002422, 2009.