Thomas Chacko

Professor, Faculty of Science - Earth & Atmospheric Sciences Admin


Professor, Faculty of Science - Earth & Atmospheric Sciences Admin
(780) 492-5395
4-10A Earth Sciences Building
11223 Saskatchewan Drive NW
Edmonton AB
T6G 2E3




  • Neil, B.J.C., Tersmette, D.B., Chacko, T., Heaman, L.M., Kjarsgaard, B.A., Creaser, R.A., Pearson, D.G., Stern, R.A., Dufrane, S.A., and Luo, Y. (2023) Discovery of a giant 3.3–3.1 Ga terrane in the Rae craton, Canada: Implications for the timing and extent of ancient continental growth. Geology, 51:597-601,

  • Reimink, J.R., Crow, C., Moser, D., Jacobsen, B., Bauer, A.M., and Chacko, T (2023) Quantifying the effect of late bombardment on terrestrial zircons. EPSL, 604:118007,

  • Stachel, T., Cartigny, P., Chacko, T., and Pearson, D.G. (2022) Carbon and nitrogen in mantle-derived diamonds. Rev. Min. Geochem., 88:809-876.

  • Bilak, G.S., Niemetz, K., Reimink, J.R., Reyes, A.V., Chacko, T., Dufrane, S.A., Belosevic, M., and Ketchum, J.W.F. (2022) Evaluating the age distribution of exposed crust in the Acasta Gneiss Complex using detrital zircons in Pleistocene eskers. Geochem., Geophys., Geosys., 23:e2022GC010380.

  • Toma, J., Creaser, R.A., Card, C., Stern, R.A., Chacko, T., and Steele-MacInnis, M. (2022) Re-Os geochronology of graphite. Geochim. Cosmochim. Acta, 323:164-182.

  • Pearson, D.G.., Scott, J.M., Liu, J., Schaeffer, A., Hongliang Wang, L., van Hunen, J., Szilas, K., Chacko, T., Kelemen, P.B. (2021) Deep continental roots, Nature, 596:199-211.

  • Gruber, B., Chacko, T., Pearson, D.G., Currie, C., and Menzies, A. (2021) Heat production and Moho temperatures in cratonic crust: evidence from lower crustal xenoliths from the Slave craton, Lithos, 380-381:105889.

  • BAUER, A.N., REIMINK, J.R., CHACKO, T., FOLEY, B.J., SHIREY, S.B., PEARSON, D.G. (2020) Hafnium isotopes in zircons document the gradual onset of mobile-lid tectonics. Geochemical. Persperspective Letters, 14:1-6.
  • REIMINK, J.R., DAVIES, J.H.F.L., BAUER, A.N., and CHACKO, T. (2020) A comparison between zircons from the Acasta Gneiss Complex and the Jack Hills region.  Earth and Planetary Science Letters, 531:115975.
  • REIMINK, J.R., BAUER, A.N., and CHACKO, T. (2018) The Acasta Gneiss Complex. In M.J. Van Kranendonk, V.C. Bennett, and J. E. Hoffmann eds. Earth’s Oldest Rocks. 2nd Edition. Chapter 15, p. 329-347.
  • REIMINK, J.R., CHACKO, T., CARLSON, R.W., SHIREY, S.B., LIU, J., STERN, R.A., BAUER, A.N., PEARSON, D.G., and HEAMAN, L.M. (2018) Petrogenesis and tectonics of the Acasta Gneiss Complex derived from integrated petrology and 142Nd and 182W extinct radionuclide-geochemistry. Earth and Planetary Science Letters, 494: 12-22.
  • LIU, J., PEARSON, D.G., CHACKO, T., LUO, Y. (2018) A reconnaissance view of tungsten reservoirs in some crustal and mantle rocks: implications for interpreting W isotopic compositions and crust-mantle recycling. Geochimica et Cosmochimica Acta, 223: 300-318.
  • WANG, E., UNSWORTH, M., and CHACKO, T. (2018) Geoelectric structure of the Great Slave Lake shear zone in northwest Alberta: implications for structure and tectonic history. Canadian Journal of Earth Sciences, 55: 295-307.
  • FISHER C.M., PATON, C., PEARSON, D.G., SARKAR, C., LUO, Y., TERSMETTE, D.B., and CHACKO, T. (2017) Data reduction of laser ablation split-stream (LASS) analyses using newly developed features within Iolite: With applications to Lu-Hf + U-Pb in detrital zircon and Sm-Nd+U-Pb in igneous monazite. Geochemistry, Geophysics, Geosystems, 18: 4604-4622.
  • FORSTER, B., AULBACH, S., SYMES, C., GERDES, A., HOFER, H.E., and CHACKO, T. (2017) A reconnaissance study of Ti-minerals in cratonic granulite xenoliths and their potential as recorders of lower crust formation and evolution. Journal of Petrology, 58: 2007-2034.
  • STACHEL, T., CHACKO, T. and LUTH, R.W. (2017) Carbon isotope fractionation during diamond growth in depleted peridotite: Counterintuitive insights from modelling water-maximum CHO fluids as multi-component systems. Earth and Planetary Science Letters, 473: 44-51.
  • REIMINK, J.R., DAVIES, J.H.F.L., CHACKO, T., STERN, R.A., HEAMAN, L.M., SARKAR, C., SCHALTEGGER, U., CREASER, R.A., and PEARSON, D.G. (2016) No evidence for Hadean continental crust within Earth’s oldest evolved rock unit. Nature Geoscience, 9: 777-780.
  • REIMINK, J.R., CHACKO, T., STERN, R.A. and HEAMAN L.M. (2016) The birth of a cratonic nucleus: lithogeochemical evolution of the 4.02-2.94 Ga Acasta Gneiss Complex. Precambrian Research, 281: 453-472.
  • PETTS, D.C., CHACKO, T., STACHEL, T., STERN, R.A. and HEAMAN, L.M. (2015) A nitrogen isotope fractionation factor between diamond and its parental fluid derived from detailed SIMS analysis of a gem diamond and theoretical calculations. Chemical Geology, 410: 188-200.
  • REIMINK, J.R., CHACKO, T., STERN, R.A. and HEAMAN, L.M. (2014) Earth’s earliest evolved crust generated in an Iceland-like setting. Nature Geoscience 7: 529-533.
  • SMART K.A., CHACKO, T., SIMONETTI, A.. SHARP, Z.D. and HEAMAN, L.M (2014) A record of Paleoproterozoic subduction preserved in the northern Slave cratonic mantle: Sr-Pb-O isotope and trace-element investigations of eclogite xenoliths from the Jericho and Muskox kimberlites. Journal of Petrology, 55: 549-583.
  • PARTIN, C.A., BEKKER, A., SYLVESTER, P.J., WODICKA, N., STERN, R.A., CHACKO, T. and HEAMAN, L.M. (2014) Filling in the juvenile magmatic gap: evidence for uninterrupted Paleoproterozoic plate tectonics. Earth and Planetary Science Letters 388: 123-133.
  • SMART, K.A., CHACKO, T., STACHEL, T., TAPPE, S., STERN, R.A., and ICKERT, R.B. (2012) Eclogite formation beneath the northern Slave Craton constrained from diamond inclusions: oceanic lithosphere origin without a crustal signature. Earth and Planetary Science Letters 319-320: 165-177.
  • Majorowicz, J., Unsworth, M., Chacko, T., Gray, A., Heaman, L.M., Potter, D.K., Schmitt, D. and Babadagli, T. (2012) Geothermal energy as a source of heat for oil sands processing in northern Alberta, Canada. In F.J. Hein, D. Leckie, S. Larter and J. Suter eds. Heavy-oil and oil sand petroleum systems in Alberta and beyond. AAPG Studies in Geology, 64: 1-22.
  • SMART, K.A., CHACKO, T., STACHEL, T., MUEHLENBACHS, K., STREN, R.A., and HEAMAN, L.M(2011) Diamond growth from oxidized carbon sources beneath the northern Slave craton: a d13C-N study of eclogite-hosted diamonds from the Jericho kimberlite. Geochimica et Cosmochimica Acta 75: 6027-6047.
  • LABOTKA, T.C., COLE, D.R., FAYEK, M.J. and CHACKO T.(2011) An experimental study of the diffusion of C and O in calcite in mixed CO2-H2O fluid. American Mineralogist, 96:1262-1269.
  • AULBACH, S., KRAUSS, C., CREASER R.A., STACHEL, T., HEAMAN, L.M., MATEEV, S. and CHACKO, T. (2010) Granulite sulfides as tracers of lower crustal origin and evolution: An example from the Slave craton, Canada. Geochimica et Cosmochimica Acta 74: 5368-5381.
  • DAVIES, T., RICHARDS, J.P., CREASER, R.A., HEAMAN, L.M., CHACKO, T., SIMONETTI, A., WILLIAMSON, J. and MCDONALD, D.W.(2010) Paleoproterozoic age relationships in the Three Bluffs Archean iron formation-hosted gold deposit, Committee Bay Greenstone Belt, Nunavut, Canada. Exploration and Mining Geology 19: 55-80.
  • BRIDGE, N.J., BANERJEE, N.R., MUELLER, W., MUEHLENBACHS, K. and CHACKO T. (2010) A volcanic habitat for early life preserved in the Abitibi Greenstone Belt, Canada. Precambrian Research, 179:88-98.
  • SMART, K.A., HEAMAN, L.M. CHACKO, T., SIMONETTI, A., KOPYLOVA, M., MAH, D. and DANIELS, D.(2009) The nature and origin of high-MgO diamond eclogites from the Jericho Kimberlite, Canada. Earth and Planetary Science Letters 284: 527-537.
  • CHACKO, T. and DEINES, P. (2008): Theoretical calculation of oxygen isotope fractionation factors in carbonate systems. Geochimica et Cosmochimica Acta, 72: 3642-3660
  • NAIR, R. and CHACKO, T. (2008): The role of oceanic plateaus in subduction initiation and origin of continental crust. Geology, 36: 583-586
  • SIMONETTI, A., HEAMAN, L.M. and CHACKO, T. (2008): Use of discrete-dynode secondary electron multipliers with Faradays - A 'reduced volume' approach for in situ U-Pb dating of accessory minerals within petrographic thin section by LA-MC-ICP-MS. Mineralogical Association of Canada Short Course Series, 40: 241-264
  • FRENCH, J.E., HEAMAN, L.M., CHACKO, T. and SRIVASTIVA, R. (2008): 1891-1883 Ma Southern Bastar-Cuddapah mafic igneous events, India: A newly recognized large igneous province, Precambrian Research, 160: 308-322
  • SCHULTZ, M.E.J., CHACKO, T., HEAMAN, L.M., SANDEMAN, H.A., SIMONETTI, A. and CREASER, R.A. (2007): Queen Maud block: A newly recognized Paleoproterozoic (2.4-2.5 Ga) terrane in northwest Laurentia. Geology, 35: 707-710
  • HARTLAUB, R.P., HEAMAN, L.M., CHACKO, T and ASHTON, K.E. (2007): Circa 2.3-Ga magmatism in the Arrowsmith Orogeny, Uranium City region, western Churchill Craton, Canada. Journal of Geology, 115: 181-195
  • SIMONETTI, A., HEAMAN, L.M., CHACKO, T. and BANERJEE, N.R. (2006): In-situ petrographic thin section U-Pb dating of zircon, monazite and titanite using laser-ablation-MC-ICP-MS. International Journal of Mass Spectrometry, 223: 87-97
  • HARTLAUB, R.P., CHACKO, T., HEAMAN, L.M., CREASER, R.A., ASHTON, K. and SIMONETTI, A. (2005): Ancient (Meso- to Paleoarchean) crust in the Rae Province, Canada: evidence from Sm-Nd and U-Pb constraints. Precambrian Research, 141: 137-153
  • HEAMAN, L.M., CREASER, R.A., COOKENBOO, H.O. and CHACKO, T. (2005): Multi-stage modification of the northernSlave mantle lithosphere: evidence from zircon- and diamond-bearing eclogite xenolilths entrained in the Jericho kimberlite, Canada. Journal of Petrology, 47: 821-858
  • HARTLAUB, R.P., HEAMAN, L.M., ASHTON, K.E. and CHACKO, T. (2004): The Archean Murmac Bay Group: evidence for a giant Archean rift in the Rae Province, Canada. Precambrian Research, 131: 345-372
  • PATTISON, D.R.M., CHACKO, T., FARQUHAR, J. and McFARLANE, C.R.M. (2003): Temperatures of granulite-facies metamorphism: constraints from experimental phase equilibria and thermobarometry corrected for retrograde exchange. Journal of Petrology, 43: 2121-2142
  • NAIR, R. and CHACKO, T. (2002): Fluid-absent melting of high-grade semi-pelites: P-T constraints on orthopyroxene formation and implications for granulite genesis. Journal of Petrology, 43: 2121-2142
  • FRENCH, J.E., HEAMAN, L.M., and CHACKO, T. (2002): Feasibility of chemical U-Th-total Pb baddeleyite dating by electron microprobe. Chemical Geology, 188: 85-104
  • CREASER, R.A., SANNIGRAHI, P., CHACKO, T. and SELBY, D. (2002): Further evaluation of the Re-Os geochronometer in organic-rich sedimentary rocks: a test of hydrocarbon maturation effects in the Exshaw Formation, Western Canada Sedimentary Basin. Geochimica et Cosmochimica Acta, 66: 3441-3452
  • CHACKO, T., COLE, D.R., and HORITA, J. (2001): Equilibrium oxygen, hydrogen and carbon isotope fractionation factors applicable to geological systems. In Valley, J.W. and Cole, D.R. eds., Reviews in Mineralogy and Geochemistry, 43: 1-81.


Research area

metamorphic petrology, stable isotope geochemistry, crustal evolution, Precambrian geology, granulites, granites

Research interest

I specialize in the study of metamorphic rocks, in particular the processes associated with high-temperature metamorphism and melting in the deep continental crust. I am also interested in how these small-scale processes relate to the larger-scale process of continental crust formation and continental assembly. Another thrust of my research is the experimental determination of oxygen and hydrogen isotope fractionation factors between minerals and fluids. In pursuit of these research goals, I use a variety of techniques including field and petrographic observations, electron microprobe and stable isotope analysis and high-pressure experimental studies using the piston cylinder apparatus. Field areas include the Taltson Magmatic Zone of northeast Alberta, the Slave Province in the Northwest Territories, and the southern Indian granulite terrane.

Research opportunity

Current Research Projects (in collaboration with graduate students & colleagues)

  • Secular variations in the metamorphic temperatures of collisional orogenic belts
  • Development of standards for chemical Th-U-Pb dating of monazite by electron microprobe
  • Petrological, geochemical and geochronological studies in the Cardamom Hills charnockite massif, southern Indian granulite terrane
  • Experimental determination of hydrogen diffusion rates in hydrous minerals
  • Fluid-absent melting of hydrated basalts, basaltic komatiite, and komatiite


EAS 332 - Metamorphic Petrology

An introduction to the classification and genesis of metamorphic rocks in light of field, petrographic and geochemical data. Prerequisites: EAS 320 and 331 or consent of the instructor. [Faculty of Science]

EAS 432 - Precambrian Geology

Precambrian geological evolution of Earth focusing on development of the continental lithosphere. Geochemical evolution of the crust and mantle as well as the atmosphere and hydrosphere. Special reference to the evolution, stratigraphy, petrology and geochronology of the Canadian Shield. Prerequisite: EAS 320 and 331. [Faculty of Science]

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