Judith Ann McKenzie (May 4, 1942 – August 11, 2023) was an American biogeochemist known for her research on past climate change, chemical cycles in sediments, and geobiology.

Judith Ann McKenzie
Born(1942-05-04)May 4, 1942
DiedAugust 11, 2023(2023-08-11) (aged 81)
Alma materUniversity of Colorado, Boulder; ETH Zurich
Scientific career
ThesisIsotope study of the hydrology and the co-existing carbonate phase from site of recent dolomitization the coastal sabkha of Abu Dhabi, Persian Gulf (1976)

Education and career

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McKenzie had an M.S. in chemistry from the University of Colorado, Boulder (1970), studied at Scripps Institution of Oceanography, and earned her Ph.D. from the Institute of Geology at ETH Zurich (1976).[1][2] McKenzie remained at ETH as a postdoc until moving to the University of Florida Gainesville in 1985 where she was promoted to tenured professor in 1987.[3] She returned to ETH Zurich and was appointed full professor in 1996 and later retired at the end of September 2007.[4]

McKenzie served as president of the International Association of Sedimentologists (2002–2006)[5][6] and the Geochemical Society (2002-2003).[7][6] McKenzie has also worked within the International Ocean Drilling Program (IODP), specially within the Swiss contribution to the project[8] and from 2006 to 2008 she presented lectures on the deep biosphere in the distinguished lecture series of the European Consortium for Ocean Research Drilling.[9]

In a 2011 interview conducted by the European Association of Geochemistry, McKenzie reflected on her career arc from her Ph.D. research on the chemistry of dolomites in Abu Dhabi to the research of her final postdoc on the geobiology of the dolomites in the same area.[10] During the interview she noted this shift from focusing solely on the geology of rocks to an additional consideration of the biology of the rocks is reflected in the shift of the community at large.[10]

McKenzie has enabled the ability of students to participate in field work through establishing summer schools within the International Association of Sedimentologists[6] and by establishing the Judith McKenzie field work award for graduate students using funds from the Emile Argand Award she received in 2016.[11][12] McKenzie received multiple awards (details below) and has shared insight on how to improve the diversity of award winners within geosciences.[13]

Research

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McKenzie's research used the sedimentary record to define past climates and change over time. This research partially relies on quantifying stable isotopes of dolomite in Abu Dhabi sabkhas[14] and evaporites in Sicily.[15] She has also examined the impact of biological activity on the carbon and nitrogen isotopic ratio in sediments.[16] Cindy Lee, McKenzie, and Michael Sturm used stable isotopes to examine fluxes in particulate matter in a Swiss lake.[17] In the same lake David Hollander and McKenzie examined the fractionation of carbon isotopes as a potential measure of the past atmospheric carbon dioxide concentrations.[18]

McKenzie's work on the 'dolomite problem', an enigma whereby the past prevalence of dolomite is higher than what is found in modern environments,[19] has recently revealed that dolomite is precipitated by bacteria living under anoxic conditions which was first observed in the laboratory with sulfate-reducing Desulfovibrio,[20] and subsequently with microbes isolated from a coastal lagoon in Brazil[21][22][23] and in the coastal sabkha of Abu Dhabi.[24][25]

Later life and death

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McKenzie retired as a full Professor of Earth System Sciences at ETH Zurich in 2007.

Judith Ann McKenzie died on August 11, 2023, at the age of 81.[26]

Awards

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References

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  1. ^ a b "McKenzie, Judith Ann, Prof. Dr. | ETH Zurich". erdw.ethz.ch. European Association of Geochemistry. Retrieved 2021-05-30.
  2. ^ McKenzie, Judith Ann (1976). Isotope study of the hydrology and the co-existing carbonate phase from site of recent dolomitization the coastal sabkha of Abu Dhabi, Persian Gulf (Doctoral Thesis thesis). ETH Zurich.
  3. ^ "192 faculty members promoted, tenured; some both at the same time". The Independent Florida Gator. October 6, 1987.
  4. ^ "McKenzie, Judith Ann, Prof. Dr. | ETH Zurich". erdw.ethz.ch. Retrieved 2021-05-30.
  5. ^ "2002 Officer and Director Candidates". The Geochemical News. No. 108. July 2001. p. 9. ISSN 0016-7010.
  6. ^ a b c d Swart, Peter K. (2015). "Citation of Judith McKenzie for Honorary Membership of the International Association of Sedimentologists". Sedimentology. 62 (4): 1102. doi:10.1111/sed.12208. S2CID 128901899.
  7. ^ "Past Presidents | Geochemical Society". www.geochemsoc.org. Retrieved 2021-05-30.
  8. ^ Becker, Keir; Austin, James A.; Exon, Neville; Humphris, Susan; Kastner, Miriam; McKenzie, Judith A.; Miller, Kenneth G.; Suyehiro, Kiyoshi; Taira, Asahiko (2019). "50 Years of Scientific Ocean Drilling". Oceanography. 32 (1): 17–21. doi:10.5670/oceanog.2019.110. hdl:1885/196759. ISSN 1042-8275. JSTOR 26604941. S2CID 135374057.
  9. ^ "ECORD Distinguished Lecturer Programme". ECORD: European Consortium for Ocean Research Drilling. Retrieved 2021-05-30.
  10. ^ a b Interview Judith McKenzie.MPG, European Association of Geochemistry, April 11, 2011, retrieved 2021-05-30
  11. ^ a b "Grants | IAS". sedimentologists.org. Retrieved 2021-05-30.
  12. ^ "Launching the Judith McKenzie Field Work Award". The Newsletter of the International Association of Sedimentologists. 2020.
  13. ^ Ball, Jessica; Davidson, Eric; Holloway, Tracey; Holmes, Mary Anne; McKenzie, Judith Ann; Mukasa, Sam; Paredes, Beth; Pieters, Carle; Sivapalan, Murugesu; Vrugt, Jasper (2015-03-10). "Improving Your Success in AGU Honors". Eos. doi:10.1029/2015EO026143. ISSN 2324-9250.
  14. ^ McKenzie, Judith A. (1981-03-01). "Holocene Dolomitization of Calcium Carbonate Sediments from the Coastal Sabkhas of Abu Dhabi, U.A.E.: A Stable Isotope Study". The Journal of Geology. 89 (2): 185–198. doi:10.1086/628579. ISSN 0022-1376. S2CID 129259374.
  15. ^ McKenzie, J.A.; Jenkyns, H.C.; Bennet, G.G. (1979-01-01). "Stable isotope study of the cyclic diatomite—Claystones from the tripoli formation, Sicily: A prelude to the Messenian salinity crisis". Palaeogeography, Palaeoclimatology, Palaeoecology. 29: 125–141. doi:10.1016/0031-0182(79)90077-4. ISSN 0031-0182.
  16. ^ Lehmann, Moritz F.; Bernasconi, Stefano M.; Barbieri, Alberto; McKenzie, Judith A. (2002-10-15). "Preservation of organic matter and alteration of its carbon and nitrogen isotope composition during simulated and in situ early sedimentary diagenesis". Geochimica et Cosmochimica Acta. 66 (20): 3573–3584. doi:10.1016/S0016-7037(02)00968-7. ISSN 0016-7037.
  17. ^ Lee, Cindy; McKenzie, Judith A.; Sturm, Zurich Michael (1987). "Carbon isotope fractionation and changes in the flux and composition of particulate matter resulting from biological activity during a sediment trap experiment in Lake Greifen, Switzerland1". Limnology and Oceanography. 32 (1): 83–96. doi:10.4319/lo.1987.32.1.0083. ISSN 1939-5590. S2CID 131511326.
  18. ^ Hollander, David J.; McKenzie, Judith A. (1991-09-01). "CO2 control on carbon-isotope fractionation during aqueous photosynthesis: A paleo-pCO2 barometer". Geology. 19 (9): 929–932. doi:10.1130/0091-7613(1991)019<0929:CCOCIF>2.3.CO;2. ISSN 0091-7613.
  19. ^ Arvidson, Rolf S.; Mackenzie, Fred T. (1999-04-01). "The dolomite problem; control of precipitation kinetics by temperature and saturation state". American Journal of Science. 299 (4): 257–288. doi:10.2475/ajs.299.4.257. ISSN 0002-9599. S2CID 49341088.
  20. ^ Vasconcelos, Crisogono; McKenzie, Judith A.; Bernasconi, Stefano; Grujic, Djordje; Tiens, Albert J. (1995). "Microbial mediation as a possible mechanism for natural dolomite formation at low temperatures". Nature. 377 (6546): 220–222. doi:10.1038/377220a0. ISSN 1476-4687. S2CID 4371495.
  21. ^ Crisogono Vasconcelos, Judith (1997). "Microbial Mediation of Modern Dolomite Precipitation and Diagenesis Under Anoxic Conditions (Lagoa Vermelha, Rio de Janeiro, Brazil)". SEPM Journal of Sedimentary Research. 67. doi:10.1306/d4268577-2b26-11d7-8648000102c1865d. ISSN 1527-1404.
  22. ^ Warthmann, Rolf; Lith, Yvonne van; Vasconcelos, Crisógono; McKenzie, Judith A.; Karpoff, Anne Marie (2000-12-01). "Bacterially induced dolomite precipitation in anoxic culture experiments". Geology. 28 (12): 1091–1094. doi:10.1130/0091-7613(2000)28<1091:BIDPIA>2.0.CO;2. ISSN 0091-7613.
  23. ^ Warthmann, Rolf; Vasconcelos, Crisogono; Sass, Henrik; McKenzie, Judith A. (2005). "Desulfovibrio brasiliensis sp. nov., a moderate halophilic sulfate-reducing bacterium from Lagoa Vermelha (Brazil) mediating dolomite formation". Extremophiles. 9 (3): 255–261. doi:10.1007/s00792-005-0441-8. hdl:20.500.11850/32616. ISSN 1431-0651. PMID 15856133. S2CID 20357645.
  24. ^ Bontognali, Tomaso R. R.; Vasconcelos, Crisógono; Warthmann, Rolf J.; Bernasconi, Stefano M.; Dupraz, Christophe; Strohmenger, Christian J.; McKENZIE, Judith A. (2010). "Dolomite formation within microbial mats in the coastal sabkha of Abu Dhabi (United Arab Emirates)". Sedimentology. 57 (3): 824–844. doi:10.1111/j.1365-3091.2009.01121.x. ISSN 1365-3091. S2CID 129617756.
  25. ^ Bontognali, Tomaso R. R.; Vasconcelos, Crisógono; Warthmann, Rolf J.; Bernasconi, Stefano M.; Dupraz, Christophe; Strohmenger, Christian J.; McKENZIE, Judith A. (2010). "Dolomite formation within microbial mats in the coastal sabkha of Abu Dhabi (United Arab Emirates): Dolomite formation within microbial mats". Sedimentology. 57 (3): 824–844. doi:10.1111/j.1365-3091.2009.01121.x. S2CID 129617756.
  26. ^ Zum Gedenken an Judith McKenzie (in German)
  27. ^ "Union Fellows | AGU". www.agu.org. Retrieved 2021-05-30.
  28. ^ "Rachel Carson Lecture | AGU". www.agu.org. Retrieved 2021-05-29.
  29. ^ "Judith A. McKenzie". European Geosciences Union (EGU). Retrieved 2021-05-29.
  30. ^ "Royal Academy". www.royalacademy.dk. Retrieved 2021-05-30.
  31. ^ "Gustav-Steinmann-Medaille 2008 an Judith McKenzie" (PDF).
  32. ^ "Special issue on the IUGS Awards" (PDF). International Union of Geological Sciences. August 2017.
  33. ^ "Past Science Awards Winners". www.sepm.org. Retrieved 2021-05-30.
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