Gregory Brennecka

Staff Scientist
Nuclear and Chemical Sciences Division
Email: brennecka2@llnl.gov
Phone: +19254238502

Education

  • Arizona State University – Isotope Geochemistry Ph.D., 2007-2011
  • University of Rochester – Nuclear Chemistry coursework, 2006
  • Oregon State University – Geochemistry/Ore Deposits M.S., 2003-2006
  • University of Missouri-Columbia – Geological Sciences B.S., 2000-2003
  • Columbia College – Natural Science/Chemistry B.S., 1998-2002

Research Appointments

  • 2019 – present: Staff scientist – Lawrence Livermore National Laboratory
  • 2014 – 2019: Institut für Planetologie, University of Münster
  • 2013 – 2014: Postdoctoral Researcher – Lawrence Livermore National Lab – Nuclear Forensics Group
  • 2011 – 2013: Postdoctoral Researcher – School of Earth and Space Exploration – Arizona State University

Research Interests

Greg Brennecka's research focuses on using chemical and isotopic signatures to unravel the formation and history of a sample. The majority of his work has been on the formation and early evolution of the Solar System by looking at meteorites to better understand supernovae injection into the protoplanetary disk, early Solar System conditions and their implications for the origin of life. Greg also has used isotopic signatures to study the history of oxygen in the ocean and its influence on various mass extinction events.

Awards and Honors

  • 2016 – Nier Prize, Meteoritical Society
  • 2014-2019 – Humboldt Foundation, Sofja Kovalevskaja Award
  • 2013 – Department of Homeland Security, Postdoctoral Fellowship – LLNL
  • 2010-2011 – NASA Earth and Space Science Fellow
  • 2010 – Geological Society of America, Outstanding Student Research Award
  • 2010 – Achievement Reward for College Scientists (ARCS) scholar
  • 2009-2010 – H. Nininger Award for outstanding original research paper submitted during 2009
  • 2009 – Brian Mason Award, Meteoritical Society

Publications 

Q.R. Shollenberger and G.A. Brennecka (2020) Dy, Er, and Yb isotope compositions of meteorites and their components: Constraints on presolar carriers of the rare earth elements. Earth & Planetary Science Letters 529, 115866.

G.J. Archer, G.A. Brennecka, P. Gleißner, A. Stracke, H. Becker, T. Kleine (2019) Lack of late-accreted material as the origin of 182W excesses in the Archean mantle: Evidence from the Pilbara Craton, Western Australia. Earth & Planetary Science Letters 528, 115841.

Q.R. Shollenberger, A. Wittke, J. Render, P. Mane, S. Schuth, S. Weyer, N. Gussone, M. Wadhwa, G.A. Brennecka (2019) Combined mass-dependent and nucleosynthetic isotope variations in refractory inclusions and their mineral separates to determine their original Fe isotope compositions. Geochimica Cosmochimica Acta 263, 215-234.

Z.A. Torrano, G.A. Brennecka, C.D. Williams, S.J. Romaniello, V.K. Rai, M. Wadhwa (2019) Titanium isotope signatures of calcium-aluminum-rich inclusions from CV and CK chondrites: Implications for early Solar System reservoirs and mixing. Geochimica Cosmochimica Acta 263, 13-30.

J. Render, S. Ebert, C. Burkhardt, T. Kleine, G.A. Brennecka (2019) Titanium isotopic evidence for a shared genetic heritage of refractory inclusions from different carbonaceous chondrites. Geochimica Cosmochimica Acta 254, 40-53.

S. Ebert, J. Render, G.A. Brennecka, C. Burkhardt, A. Bischoff, S. Gerber, T. Kleine (2018) Ti isotopic evidence for a non-CAI refractory component in the inner Solar System. Earth & Planetary Science Letters 498, 257-265.

J. Render, G.A. Brennecka, S-J. Wang, L.E. Wasylenki, T. Kleine (2018) A distinct nucleosynthetic heritage for early Solar System solids recorded by Ni isotope signatures. The Astrophysical Journal 862, 1-18.

Q.R. Shollenberger, J. Render, G.A. Brennecka (2018) Er, Yb, and Hf isotopic compositions of refractory inclusions: An integrated isotopic fingerprint of the Solar System’s earliest reservoir. Earth & Planetary Science Letters 495, 12-23.

Q.R. Shollenberger, L.E. Borg, J. Render, S. Ebert, A. Bischoff, S.S. Russell, G.A. Brennecka (2018) Isotopic coherence of refractory inclusions from CV and CK meteorites: Evidence from multiple isotope systems. Geochimica Cosmochimica Acta. 228, 62-80.

G.A. Brennecka, Y. Amelin, T. Kleine (2018) Uranium isotope fractionation in Muonionalusta troilite and the absolute age of the IVA iron meteorite core. Earth & Planetary Science Letters 490, 1-10.

C.D.K. Herd et al. (2017) The Northwest Africa 8159 Martian Meteorite: Expanding the Martian Sample Suite to the Early Amazonian. Geochimica Cosmochimica Acta 218, 1-26.

T.S. Kruijer, T. Kleine, L.E. Borg, G.A. Brennecka, A.J. Irving, A. Bischoff, C.B. Agee (2017) The early differentiation of Mars inferred from Hf–W chronometry. Earth & Planetary Science Letters 474, 345-354.

G.A. Brennecka, T. Kleine (2017) A low abundance of 135Cs in the early Solar System from barium isotopic signatures of volatile-depleted meteorites. The Astrophysical Journal Letters 837, L9-L12.

G.A. Brennecka, L.E. Borg, S.J. Romaniello, A.K. Souders, Q.R. Shollenberger, N.E. Marks, M. Wadhwa (2017) renewed search for short-lived 126Sn in the early Solar System: Hydride generation MC-ICPMS for high sensitivity Te isotopic analysis. Geochimica Cosmochimica Acta 201, 331-344.

G. Budde, C. Burkhardt, G.A. Brennecka, M. Fischer-Gödde, T.S. Kruijer, T. Kleine (2016) Molybdenum isotopic evidence for the origin of chondrules and a distinct genetic heritage between carbonaceous and non-carbonaceous meteorites. Earth & Planetary Science Letters 454, 293-303.

R. Bezard, M. Fischer-Gödde, C. Hamelin, G.A. Brennecka, T. Kleine (2016) The role of magmatic processes and crustal recycling on the molybdenum stable isotopic composition of Mid-Ocean Ridge Basalts. Earth & Planetary Science Letters 453, 171–181.

C. Burkhardt, L.E. Borg, G.A. Brennecka, Q.R. Shollenberger, N. Dauphas, T. Kleine (2016) A nucleosynthetic origin of the Earth's anomalous 142Nd composition. Nature 537, 394-398.

S. Domagal-Goldman, et al. (2016) The Astrobiology Primer v2.0. Astrobiology 16, 561-653.

L.E. Borg, G.A. Brennecka, S.J.K. Symes (2016) Accretion Timescale and Impact History of Mars Deduced from Isotopic Systematics of Martian Meteorites. Geochimica Cosmochimica Acta 175, 150-167.

G.A. Brennecka, G. Budde, T. Kleine (2015) Uranium isotopic composition and absolute ages of Allende chondrules. Meteoritics & Planetary Science 50, 1995-2002.

L.J. Spivak-Birndorf, A. Bouvier, G. Benedix, S. Hammond, G.A. Brennecka, K. Howard, N. Rogers, M. Wadhwa,  P.A. Bland, P. Spurný, M.C. Towner (2015) Trace element geochemistry and chronology of Bunburra Rockhole, a unique asteroidal basalt. Meteoritics & Planetary Science 50, 958-975.

A. Goldmann, G.A. Brennecka, J. Noordmann, S. Weyer, M. Wadhwa (2015) The uranium isotopic composition of the Earth and the Solar System. Geochimica Cosmochimica Acta 148, 145-158.

G.A. Brennecka, L.E. Borg, M. Wadhwa. (2014) Insights into the Martian Mantle: The Age and Isotopics of the Meteorite Fall Tissint. Meteoritics & Planetary Science 49, 412-418.

B. Kendall, G.A. Brennecka, S. Weyer, A.D. Anbar. (2013) Oxidative uranium mobilization at 2.50 Ga. Chemical Geology, 362, p.105-114.

G.A. Brennecka, L.E. Borg, M. Wadhwa. (2013) Evidence for supernova injection into the solar nebula and the decoupling of r-process nucleosynthesis Proceedings of the National Academy of Sciences 110 p. 17241-17246.

F. Moynier, T. Fujii, G.A. Brennecka, S. Nielsen (2013) Nuclear field shift in natural environments. Comptes Rendus Geoscience 345, p. 150-159.

G.A. Brennecka and M. Wadhwa. (2012) Uranium isotope compositions of the basaltic angrite meteorites and the chronological implications for the early Solar System. Proceedings of the National Academy of Sciences, 109 p. 9299-9303.

G.A. Brennecka, A.D. Herrmann, T.J. Algeo, A.D. Anbar. (2011) Rapid expansion of oceanic anoxia immediately before the end-Permian mass extinction. Proceedings of the National Academy of Sciences, 108 p. 17631.

A. Bouvier, L. J. Spivak-Birndorf, G. A. Brennecka, M. Wadhwa (2011). New constraints on early Solar System chronology from Al-Mg and U-Pb isotope systematics in the unique basaltic achondrite Northwest Africa 2976. Geochimica et Cosmochimica Acta, 75 p. 5310–5323.

G.A. Brennecka, L.E. Wasylenki, S. Weyer, A.D. Anbar (2011). Uranium isotope fractionation during adsorption to Mn-oxyhydroxides.  Environmental Science & Technology 45, p.1370–1375.

G.A. Brennecka, S. Weyer, M. Wadhwa, P.E. Janney, J. Zipfel and A.D. Anbar (2010). 238U/235U Variations in Meteoritic Material: Extant 247Cm and implications for Pb-Pb dating. Science 327, p.449.

G.A. Brennecka, L.E. Borg, I.D. Hutcheon, M.A. Sharp, A.D. Anbar (2010). Natural Variations in Uranium isotope ratios of Uranium Ore Concentrates: Understanding the fractionation mechanism. Earth & Planetary Science Letters 291 p. 228-233.

L. Borg, A. Gaffney, C. Shearer, D. DePaolo, I. Hutcheon, T. Owens, E. Ramon, G. Brennecka (2009) Mechanisms for incompatible-element enrichment on the Moon deduced from the lunar basaltic meteorite Northwest Africa 032. Geochimica Cosmochimica Acta 73, 3963-3980.