Associate Professor Sebastian Tappe (Dr. rer. nat. & Pri. Nat. Sci.)

Born on the Baltic Sea coast in Germany, Sebastian studied geology at the Ernst-Moritz-Arndt University (M.Sc., 2001), followed by studies in petrology and isotope geochemistry at the Johannes-Gutenberg University in Mainz (Ph.D., 2005). After postdoctoral research at the Max-Planck Institute for Chemistry (Germany, 2006) and the University of Alberta (Canada, 2007-2008), he moved to Toronto to work for De Beers Canada Inc. as a Geosciences Specialist (2008-2009). Between 2009 and 2011, Sebastian was a Research Associate in the Radiogenic Isotope Facility at the University of Alberta, where he managed a U-Pb clean-lab and mass spectrometer (TIMS). After an appointment as Assistant Professor (Akademischer Rat a.Z.) at the Westfälische Wilhelms University in Münster (Germany, 2011-2012), Sebastian moved to South Africa to re-join De Beers in the Johannesburg Headquarters in 2013. After spending over 2 years in global diamond exploration with De Beers as a Senior Specialist, Sebastian returned to academia in June 2015 as an Associate Professor in the Department of Geology, University of Johannesburg.

Sebastian’s research interests include melting processes within the Earth’s mantle, particularly the formation of alkaline and carbonate-rich magmas, and their roles within the geochemical cycle. Furthermore, he has conducted petrologic and isotope geochemical studies on mantle-derived xenoliths with the goal of better understanding the formation and fragmentation of cratonic lithosphere. Recent work has focused on isotopic analysis, including U-Pb perovskite geochronology, of kimberlites from North America, Brazil, Siberia, and Africa. These studies are conducted to develop models for the origin of diamond-bearing ultramafic magmas, and to better understand the geodynamic conditions under which they form. At the University of Johannesburg, this research direction will be complemented by a diverse range of projects designed to understand the formation and geologic distribution of critical raw materials with strong emphasis on commodities that are of strategic importance to the world economy with Africa as a major or emerging supplier.

Sebastian is a member of the Geochemical Society (ID 174372), the American Geophysical Union (ID 304236), the Geological Society of South Africa (ID 969285), and the South African Council for Natural Scientific Professions (ID 400174/13). Since 2013 he holds Honorary Researcher status at the School of Geosciences, University of the Witwatersrand.

Research Opportunity:

I intend to attract interested students to work on the following subjects:

  • Nature and origin of global kimberlite magmatism (e.g., Africa, Asia, North America)
  • Kimberlite pipe emplacement models and micro-/macrodiamond relationships
  • Alkaline and carbonatite melt generation in “hot” Archean subduction zones
  • Mineralogy (in particular trace element compositions) of diamond-bearing lamproites
  • Depth(s) and tectonic setting(s) of Archean continental mantle lithosphere formation
  • Geochemistry of diamonds with implications for ancient and deep volatile cycles
  • Burial and unroofing histories of cratons and their mineral deposits by means of U-Th/He thermochronology
    • Petrology and isotope geochemistry of REE- and U-deposits
    • Development of innovative geochemical tools for mineral exploration

Selected Peer-reviewed Publications (since 2010; *denotes student paper):

Tappe, S., Smart, K.A., Stracke, A., Romer, R.L., Prelevic, D. & van den Bogaard, P. (2015). Convecting mantle origin for alkaline basalts at a rifted craton edge: 40Ar/39Ar age and Sr-Nd-Hf-Pb isotope evidence from Jurassic volcanics, SW Baltic Shield, Sweden. Geochimica et Cosmochimica Acta,accepted manuscript, in revision.

Joy, S., Jelsma, H., Armstrong, R. & Tappe, S. (2015). SHRIMP U-Pb zircon provenance of the Sullavai Group of Pranhita-Godavari basin and Bairenkonda Formation of Cuddapah basin, with implications for the southern Indian Proterozoic tectonic architecture. Journal of Asian Earth Sciences,accepted manuscript, in revision.

Thorarinsson, S.B., Holm, P.M., Tappe, S., Heaman, L.M. & Prægel, N.-O. (2015). U-Pb geochronology of the Eocene Kærven Igneous Complex, East Greenland: Constraints on the Iceland hotspot track during the rift-to-drift transition. Geological Magazine, in press.

Tappe, S., Kjarsgaard, B.A., Kurszlaukis, S., Nowell, G.M. & Phillips, D. (2014). Petrology and Nd-Hf isotope geochemistry of the Neoproterozoic Amon kimberlite sills, Baffin Island (Canada): Evidence for deep mantle magmatic activity linked to supercontinent cycles. Journal of Petrology 55, 2003-2042.

*Sun, J., Liu, C.-Z., Tappe, S., Kostrovitsky, S.I., Wu, F.-Y., Yakovlev, D., Yang, Y.H. & Yang, J.H. (2014). Repeated kimberlite magmatism beneath Yakutia and its relationship to Siberian flood volcanism: Insights from in situ U-Pb and Sr-Nd perovskite isotope analysis. Earth and Planetary Science Letters 404, 283-295.

Tappe, S., Pearson, D.G., Kjarsgaard, B.A., Nowell, G.M. & Dowall, D. (2013). Mantle transition zone input to kimberlite magmatism near a subduction zone: Origin of anomalous Nd-Hf isotope systematics at Lac de Gras, Canada. Earth and Planetary Science Letters 371-372, 235-251.

Tappe, S., Pearson, D.G. & Prelevic, D. (2013). Kimberlite, carbonatite, and potassic magmatism as part of the geochemical cycle. Chemical Geology 353, 1-3.

*Beyer, C., Berndt, J., Tappe, S. & Klemme, S. (2013). Trace element partitioning between perovskite and kimberlite to carbonatite melt: New experimental constraints. Chemical Geology 353, 132-139.

*Donatti-Filho, J.P., Tappe, S., Oliveira, E.P. & Heaman, L.M. (2013). Age and origin of the Neoproterozoic Brauna kimberlites: Melt generation within the metasomatized base of the São Francisco craton, Brazil. Chemical Geology 353, 19-35.

Tappe, S., Steenfelt, A. & Nielsen, T.F.N. (2012). Asthenospheric source of Neoproterozoic and Mesozoic kimberlites from the North Atlantic craton, West Greenland: New high-precision U-Pb and Sr-Nd isotope data on perovskite. Chemical Geology 320-321, 113-127.

Tappe, S. & Simonetti, A. (2012). Combined U-Pb geochronology and Sr-Nd isotope analysis of the Ice River perovskite standard, with implications for kimberlite and alkaline rock petrogenesis. Chemical Geology 304-305, 10-17.

*Smart, K.A., Chacko, T., Stachel, T., Tappe, S., Stern, R.A. & Ickert, R.B. (2012). Eclogite formation beneath the northern Slave craton constrained by diamond inclusions: Oceanic lithosphere origin without a crustal signature. Earth and Planetary Science Letters 319, 165-177.

*Hunt, L., Stachel, T., Grütter, H., Armstrong, J., McCandless, T.E., Simonetti, A. & Tappe, S. (2012). Small mantle fragments from the Renard kimberlites, Quebec: Powerful recorders of mantle lithosphere formation and modification beneath the eastern Superior craton. Journal of Petrology 53, 1597-1635.

Tappe, S., Smart, K.A., Pearson, D.G., Steenfelt, A. & Simonetti, A. (2011). Craton formation in Late Archean subduction zones revealed by first Greenland eclogites. Geology 39, 1103-1106.

Tappe, S., Pearson, D.G., Nowell, G.M., Nielsen, T.F.D., Milstead, P. & Muehlenbachs, K. (2011). A fresh isotopic look at Greenland kimberlites: cratonic mantle lithosphere imprint on deep source signal. Earth and Planetary Science Letters 305, 235-248.

*Thorarinsson, S.B., Holm, P.M., Tappe, S., Heaman, L.M. & Tegner, C. (2011). Late Cretaceous–Palaeocene continental rifting in the High Arctic: U–Pb geochronology of the Kap Washington Group volcanic sequence, North Greenland. Journal of the Geological Society London 168, 1093-1106.

Mitchell, R.H. & Tappe, S. (2010). Discussion of “Kimberlites and aillikites as probes of the continental lithospheric mantle”, by D. Francis and M. Patterson (Lithos v. 109, p. 72-80). Lithos 115, 288-292.