Dan Schulze (UTM)
University of Toronto Mississauga
My research is focused on the petrology of Earth’s upper mantle. Most of the interior of Earth is inaccessible for direct study, and our best samples of it exist as rare fragments accidentally brought to the surface by volcanic rocks such as kimberlite and alkaline basalt. Specific topics of interest include evidence from xenoliths for a subduction origin for some material in the subcontinental upper mantle, quantitative determination of rock types in the upper mantle from detailed study of xenolith and xenocryst suites, major element and stable isotope studies of diamonds and their mineral inclusions, and the role of indicator minerals in exploration for, and evaluation of, diamondiferous and diamond-free kimberlites. Current research involves material from Canada, United States, southern Africa, Russia and Venezuela.
X-ray computed tomographic (CT) image of diamond-bearing eclogite #13-64-131, from the Roberts Victor Mine, South Africa, the sample studied by Schulze et al. (1996). The flat top surface is a computer-visualized Aslice @. Long dimension of sample is approximately 2 cm. Colour warmth corresponds to relative density. Yellows and reds are garnet (red is fresh and yellow somewhat altered) and blues and greens are clinopyroxene. A planar veinlet contains barite. The triangular shape (right-centre) represents a Acut @ through an octahedral face of a well-formed diamond, completely enclosed within the rock. The apparent high-density of the faces is due to rimming of the diamond by secondary barite (along fractures between the diamond and host clinopyroxene). Image produced by Diana Wiese.
Van Rythoven, A.D.*, Schulze, D.J., Hauri, E., Wang., J., Shirey, S. (in press) Carbon and nitrogen chemistry of diamond crystals from three North American cratons, Chemical Geology.
Schulze, D.J., Nasdala, L. (2016) Unusual paired pattern of radiohaloes on a diamond crystal from Guaniamo (Venezuela), Lithos, v. 265, 177-181.
Schulze, D.J., Hearn, B.C., Jr., (2015) Mantle xenocrysts from the Masontown, Pennsylvania (USA) kimberlite: An ordinary mantle with Si-enriched spinel, Canadian Mineralogist, v. 53, pp. 767-773.
Schulze, D.J., Davis, D.W., Helmstaedt, H., Joy, B. (2015) Timing of the Cenozoic “Great Hydration” event beneath the Colorado Plateau: Th-Pb dating of monazite in Navajo metamorphic eclogite xenoliths. Geology, v. 43, pp. 727-730.
Hook, B.A.*, Halfar, J., Gedalof, Z., Bollman, J., Schulze, D. (2015) Stable isotope paleoclimatology of the Early Eocene using kimberlite-hosted mummified wood from the Canadian Subarctic. Biogeosciences, v. 12, pp. 5899-5914.
Hook, B.A.,* Halfar, J., Gedalof, Z., Bollman, J., Rahman, M.A., Reyes, J, Schulze, D.J. (2015) Extraction of alpha-cellulose from mummified wood for stable isotope analysis, Chemical Geology, v. 405, pp. 19-27.
Schulze, D.J., Flemming, R.L., Shepherd, P.H.M., Helmstaedt, H. (2014) Mantle-derived guyanaite in a Cr-omphacitite xenolith from Moses Rock diatreme, Utah. American Mineralogist, v. 99, pp. 1277-1283
Schulze, D.J., Harte, B., E.I.M.F., Page, F.Z., Valley, J.W., Channer, D., Jaques, L. (2013) Anticorrelation between low δ13C of eclogitic diamonds and high δ18O of their coesite and garnet inclusions requires a subduction origin. Geology, v. 41, pp. 455-458
Russell, A.K., Kitajima, K., Strickland, A., Medaris, L.G. Jr., Schulze, D.J., Valley, J.W. (2012) Eclogite-facies fluid infiltration: Constraints from δ18O zoning in garnet. Contributions to Mineralogy and Petrology, v. 165, pp. 103-116.
Nasdala, L., Grambole, D., Wildner, M., Gigler, A.M., Hainschwang, T., Zaitsev, A.M., Harris, J.W., Milledge, J., Schulze, D.J., Hofmeister, W., Balmer, W.A. (2013) Radio-colouration of diamond: a spectroscopic study, Contributions to Mineralogy and Petrology, v. 165, pp. 843-861.
Nasdala, L., Grambole, D., Harris, J.W., Schulze, D.J., Hofmeister, W. (2011) Radio-coloration of diamond. Gems and Gemology, v. 47, pp. 105-106.
Van Rythoven, A.D., McCandless, T.E., Schulze, D.J., Bellis, A., Taylor, L.A., Liu, Y. (2011) Diamond crystals and their mineral inclusions from the Lynx kimberlite dyke complex, central Quebec. Canadian Mineralogist, v. 49, pp. 691-706
Gonzaga, R.G., Lowry, D., Jacob, D., LeRoex, A., Schulze, D.J. Menzies, M.A. (2010) Eclogites and garnet pyroxenites: provenance involving polybaric melting of complex protoliths, Journal of Volcanology and Geothermal Research, v. 190, pp. 230-247.
Craven, J.A., Harte, B., Fisher, D., Schulze, D.J. (2009) Diffusion in diamond I: Carbon isotope mapping of natural diamond. Mineralogical Magazine, v. 73(2), pp. 193-200.
Van Rythoven, A.D., Schulze, D.J. (2009) In situ analysis of diamonds and their inclusions from the Diavik Mine, Northwest Territories, Canada: Mapping diamond growth, Lithos, v. 112S, pp. 870-879.
Roeder, P.L., Schulze, D.J. (2008) Crystallization of groundmass spinel in kimberlite. Journal of Petrology, v. 49, pp. 1473-1495..
Schulze, D.J., Coopersmith, H.G., Harte, B, Pizzolato, L.A. (2008) Mineral inclusions in diamonds from the Kelsey Lake Mine, Colorado, USA: Depleted Archean mantle beneath the Proterozoic Yavapai province? Geochimica et Cosmochimca Acta., v. 72, pp. 1685-1695.
Page, F.Z., Fu, B., Kita, N, Fournelle, J., Spicuzza, M.J., Schulze, D.J., Viljoen, F., Basei, A.S., Valley, J.W. (2007). Zircon megacrysts from kimberlite: new insights from oxygen isotopes, trace elements, and Ti in zircon thermometry. Geochimica et Cosmochimica Acta, v. 71, pp. 3887-3903.
Schulze, D.J., Canil, D., Channer, D.M.deR., Kaminsky, F. (2006) Layered mantle structure beneath the western Guyana Shield, Venezuela: Evidence from diamonds and xenocrysts in Guaniamo kimberlites. Geochimica et Cosmochimica Acta, v. 70, pp. 192-205.
Viljoen, K.S., Schulze, D.J., Quadling, A.G.., (2005) Contrasting Group I and Group II eclogite xenolith petrogenesis: Petrological, trace element and isotopic evidence in eclogite, garnet-websterite and alkremite xenoliths from the Kaalvallei kimberlite, South Africa. Journal of Petrology, vl 46, pp 2059-2090
Schulze, D.J. (2004) An Atlas of Minerals in Thin Section, CD-ROM format, Oxford University Press.
Schulze, D.J., Harte, B., Valley, J.W., Channer, D.M.deR. (2004) Evidence for subduction and crust-mantle mixing from a single diamond. Lithos , v. 77, pp. 349-358.
Carlson, R.W., Irving, A.J., Schulze, D.J., Hearn, B.C., Jr., (2004) Timing of Precambrian melt depletion and Phanerozoic refertilization events in the lithospheric mantle of the Wyoming Craton and adjacent Central Plains Orogen. Lithos , v, 77, pp. 453-472.
Scully, K.R., Canil, D., Schulze, D.J. (2004) The lithospheric mantle of the Archean Superior Province as imaged by garnet xenocryst geochemistry. Chemical Geology , v. 207, pp. 189-221.
Schulze, D.J., Valley, J.W., Spicuzza, M.J., Channer, D.M.de R. (2003) The oxygen isotope composition of eclogitic and peridotitic garnet xenocrysts from the La Ceniza kimberlite, Guaniamo, Venezuela, International Geology Review, v. 45, pp. 968-975.
Schulze, D.J. (2003) A classification scheme for mantle-derived garnets in kimberlite: a tool for investigating the mantle and exploring for diamonds. Lithos v. 71 (Slave-Kaapvaal Special Volume), pp. 195-213.
Jacob, D.E., Schmickler, B., and Schulze, D.J. (2003) Trace element geochemistry of coesite-bearing eclogites from the Roberts Victor kimberlite, Kaapvaal Craton, Lithos v. 71 (Slave-Kaapvaal Special Volume), pp. 337-351.
Canil, D., Schulze, D.J., Hall, D., Hearn, B.C., Jr. and Milliken, S.M. (2003) Lithospheric roots beneath western Laurentia: the geochemical signal in mantle garnets. Canadian Journal of Earth Sciences, v. 40, pp. 1027-1051.
Schulze, D.J., Harte, B., Valley, J.W., Brenan, J.M. and Channer, D.M.deR. (2003) Extreme crustal oxygen isotope signatures preserved in coesite in diamond. Nature, v. 423, pp. 68-70.
This paper was also featured in a “News and Views” story by Alison Wright, entitled “Subduction the hard way”, on p. 24 of the same issue.
Schulze, D.J., Valley, J.W., Bell, D.R., and Spicuzza, M.J. (2001) Oxygen isotope variations in Cr-poor megacrysts from kimberlite, Geochim. Cosmochim. Acta v. 65, pp. 4375-4384.
Schulze, Daniel J. (2001) Origins of chromian and aluminous spinel macrocrysts from kimberlites in southern Africa, Canadian Mineralogist, v. 39, pp. 361-376.
Schulze, D.J., Valley, J.W. and Spicuzza, KJ. (2000) Coesite eclogites from the Roberts Victor kimberlite, South Africa, Lithos, v. 54, pp. 23-32.