My Research

I am a petrologist on a quest to quantify the history of Earth’s atmosphere. A major issue for my research is that air does not precipitate a rock-forming mineral phases, meaning that there is no direct evidence to interrogate – such as a rock record. To circumvent this issue, I develop and lead an innovative array of indirect theoretical, analytical, and experimental approaches to understand the nature of long-term tectonic fluxes which govern how the interior of our planet influences the chemistry of our atmosphere.

To date, my research has generated new insights into how nitrogen- and carbon-bearing compounds are stored and cycled throughout the planet, I have drawn new links between the planet-wide carbon cycle and diamond-formation, and I have quantitatively shown how plate tectonics has altered the chemistry of Earth’s atmosphere.

I am currently working on a variety of projects with a variety of people. Below I list of my publications according to the theme of the science (Google Scholar Page).

Planetary Geoscience

Byrne, P.K., Foley, B.J., Violay, M.E.S., Heap, M.J., Mikhail, S. 2021. The Effects of Planetary and Stellar Parameters on Brittle Lithospheric Thickness. Journal of Geophysical Research: Planets

Mikhail, S., Füri, E. 2019. On the origin(s) and evolution of Earth’s carbon. Elements

Heap, M.J., Byrne, P.K., Mikhail, S. 2017. Low surface gravitational acceleration of Mars results in a thick and weak lithosphere: Implications for topography, volcanism, and hydrology. Icarus

Mikhail, S., Heap, M.J. 2017. Hot climate inhibits volcanism on Venus: constraints from rock deformation experiments and argon isotope geochemistry. Physics of the Earth and Planetary Interiors

McCubbin, F.M., Vander Kaaden, K.E., Tartèse, R., Whitson, E.S., Anand, M., Franchi, I.A., Mikhail, S., Ustunisik, G., Hauri, E.H., Wang, J., Boyce, J.W. 2015. Experimental investigation of F, Cl, and OH partitioning between apatite and Fe-rich basaltic melt at 1.5 GPa and 950-1000 °C. American Mineralogist

Mikhail, S., Sverjensky, D.A. 2014. Nitrogen speciation in upper mantle fluids and the origin of Earth’s nitrogen-rich atmosphere. Nature Geoscience

High-Temperature Carbon & Nitrogen Geochemistry (Diamond Formation & Volatile Elements)

Jacob, D.E., Mikhail, S., 2022. Polycrystalline diamonds – snapshots of rapid and episodic diamond formation in the lithospheric mantle. Reviews in Mineralogy and Geochemistry

Mikhail, S., Rinaldi, M., Mare, E.R., Sverjensky, D.A. 2021. A genetic metasomatic link between eclogitic and peridotitic diamond inclusions. Geochemical Perspectives Letters

Boocock. T.J., Mikhail, S., Prytulak, J., Di Rocco, T., Stüeken., E.E. 2020. Nitrogen mass fraction and stable isotope ratios for fourteen geological reference materials: Evaluating the applicability of Elemental Analyser versus Sealed Tube Combustion methods. Geostandards and Geoanalytical Research

McCammon, C., Bureau, H., Cleaves II, H.J., Cottrell, E., Dorfman, S.M., Kellogg, L.H., Li, J., Mikhail, S., Moussallam, Y., Sanloup, C., Thomson, A.R., Brovarone, A.V. 2020. Deep Earth Carbon Reactions Through Time and Space. American Mineralogist

Mikhail, S., Crosby, J.C., Stuart, F.M., DiNicola, L., Abernethy, F.A.J. 2019. A secretive mechanical exchange between mantle and crustal volatiles revealed by helium isotopes in 13C-depleted diamonds. Geochemical Perspective Letters

Shirey, S.B., Pearson, D.G., Walter, M.J., Aulbach, S., Brenker, F.E., Bureau, H., Burnham, A.D., Cartigny, P., Chacko, T., Frost, D.J., Hauri, E.H., Jacob, D.E., Jacobsen, S.D., Kohn, S.C., Luth, R.W., Mikhail, S., Navon, O., Nestola, F., Nimis, P., Smit, K.V., Smith, E.N., Stachel, T., Stagno, V., Steele, A., Thomassot, E., Thomson, A.R., Weiss, Y. 2019. Diamonds and the Mantle Geodynamics of Carbon: Deep Mantle Carbon Evolution from the Diamond Record. In Orcutt, B., Daniel, I., and Dasgupta, R. (Eds.) Deep Carbon: Past to Present. Cambridge University Press (Invited Contribution)

Mikhail, S., McCubbin, F.M., Jenner, F.E., Shirey, S.B., Rumble, D., Bowden, R. 2019. Diamondites: Evidence for a distinct tectono-thermal diamond-forming event beneath the Kaapvaal craton. Contributions to Mineralogy and Petrology

Broadley, M.W., Kagi, H., Burgess, R., Zedgenizov, D., Mikhail, S., Almayrac, M., Ragozin, A., Pomazansky, B., Sumino, B. 2018. Plume-lithosphere interaction, and the formation of fibrous diamonds. Geochemical Perspectives Letters

Mikhail, S., Barry, P.H., Sverjensky, D.A. 2017. The relationship between mantle pH and the deep nitrogen cycle. Geochimica Cosmochimica et Acta

Smith, C.B., Walter, M.J, Bulanova, G.P., Mikhail, S., Burnham, A.D., Gobbo, L., Kohn, S.C. 2016. Diamonds from Dachine, French Guiana: a unique record of Early Proterozoic subduction. Lithos

Mikhail, S., Howell, D. 2016. A petrological assessment of diamond as a recorder of the mantle nitrogen cycle. American Mineralogist

Howell, D., Stern, R.A., Griffin, W.L., Southworth, R., Mikhail, S., Satchel, T. 2015. Nitrogen isotope systematics and origins of mixed-habit diamonds. Geochimica Cosmochimica et Acta

Mikhail, S., Guillermier, C., Franchi, I.A., Beard, A.D., Verchovsky, A.B., Wood, I., Jones, A.P., Mileage, H.J. 2014. Empirical evidence for the fractionation of carbon isotopes between diamond and iron carbide from the Earth’s mantle. Geochemistry Geophysics Geosystems

Mikhail, S., Howell, D., Hutchison, M., Verchovsky, A.B., Warburton, P., Southworth, R., Thompson, A.R., Jones, A.P., Mileage, H.J. 2014. Constraining the internal variability of carbon and nitrogen isotopes in diamonds. Chemical Geology

Bulanova, G., Wiggers de Vries, D., Pearson, D.G., Beard, A., Mikhail, S., Smelov, A.R., Davies, G.R. 2014. Carbon recycling and polygenetic origin of eclogitic diamonds recorded by a single crystal from the Mir pipe (Yakutia). Chemical Geology

Mikhail, S., McCubbin, F.M., Howell, D. 2014. Evidence for multiple diamondite-forming events in the mantle. American Mineralogist

Mikhail, S., Kurat, G., Dubosi, G., Verchovsky, A.B., Jones, A.P., Mileage, H.J. 2013. Peridotitic and websteritic diamondites provide new information regarding mantle melting and metasomatism induced through the subduction of crustal volatiles. Geochimica Cosmochimica et Acta

Early Earth Carbon & Nitrogen Cycles

Stüeken, E.E., Boocock, T., Szilas, K., Mikhail, S., Gardiner, N.J. 2021. Reconstructing nitrogen sources to Earth's earliest biosphere at 3.7 Ga. Frontiers in Earth Science

Stüeken, E.E., Boocock, T.J., Robinson, A., Mikhail, S., Johnson, B.W. 2021. Hydrothermal recycling of sedimentary ammonium into oceanic crust and the Archean ocean at 3.24 Ga. Geology

Cousins, C.R., Mikhail, S., Foucher, F., Steele, A., Westall., F. 2020. Metamorphic evolution of carbonate-hosted microbial biosignatures. Geochemical Perspectives Letters

Zerkle, A.L., Mikhail, S. 2017. The Geobiological Nitrogen Cycle: From Microbes to the Mantle. Geobiology