Professor Robert Bolhar
School of Geosciences, University of the Witwatersrand
robert.bolhar@wits.ac.za

Research keywords: Isotope and trace element geochemistry, geo/petro-chronology, LA-ICPMS, Archaean geology

Biography: Robert is a geochemist, with 22 years of work experience in academia (5 years in the resource industry). His areas of expertise and interest, as documented in >72 peer-reviewed publications, encompass trace element and isotope geochemistry as archives of Archaean surface conditions, crust formation and evolution, geochronology and petrochronology using LA-ICPMS (eg U-Pb carbonate dating), and geochemical and isotopic fingerprinting of stone artifacts. Having been awarded two NRF-NEP grants (totaling 25 mill R) he established and directs the Wits Advanced Mass Spectrometry facility, consisting of two laser systems, quad-, SF-, collision cell MC-ICPMS instruments and a TIMS. Robert has supervised to completion eight PhD and MSc students and >20 honours students. He is a NRF-rated B2 scientist, a Fellow of the GSSA, a SACNASP-registered Professional Natural Scientist and member of the International Association of Geo-Analysts. He also serves in the editorial team of Chemical Geology.

 

Publications 2022-2023 (no abstracts, underscore indicates student/postdoc paper)

  1. Hofmann, A.*, Bolhar, R., Kuznetsov, A. (accepted) Trace element and stable (C, O) and radiogenic (Sr) isotope geochemistry of Neoarchaean stromatolitic carbonate rocks of the Zimbabwe craton. Chemical Geology
  2. Bolhar, R., Waight, T., Weaver, S., Whitehouse, M. J., Turnbull, R., Ring, U. & Maas, R. (accepted). The mid-Cretaceous Hohonu Batholith (South Island, New Zealand): Identifying magmatic sources and processes during the onset of regional extensional deformation. Chemical Geology
  3. Bolhar, R., Wilson, A. H., Tusch, J., Pettke, T., Murphy, D. & Anhauesser, C. (2023) Reworking of aged mafic crust in a Palaeoarchaean layered complex inferred from coupled Sm-Nd and Lu-Hf isotope systematics, Stolzburg Complex, Kaapvaal Craton, South Africa. Chemical Geology, 121427.
  4. Magson, J., Roelofse, F., Bybee, G, Bolhar, R. (2023) Constraints on the Nd-isotopic composition and nature of the last major influx of magma into the Bushveld Complex. Contributions to Mineralogy and Petrology, 178(3), 1-17.
  5. Ring, U., Fassoulas, C., Uysal, I. T., Bolhar, R., Tong, K. & Todd, A. (2022) Nappe imbrication within the Phyllite‐Quartzite Unit of West Crete: Implications for sustained high‐pressure metamorphism in the Hellenide Subduction Orogen, Greece. Tectonics, e2022TC007430.
  6. Tshiningayamwe, M., Bolhar, R. & Nex, P. A. (2022) Petrology, geochemistry and new U–Pb ages of the Epembe syenites and carbonatite, northwest Namibia. Journal of African Earth Sciences, 196, 104719.
  7. Tshiningayamwe, M., Bolhar, R., & Nex, P. A. M. (2022). A zircon trace element and Hf isotope geochemical study of syenites and carbonatite, exemplified by the Epembe alkaline carbonatite complex, Namibia. South African Journal of Geology 2022, 125(3-4), 307-322.
  8. Schapira, J., Rumbold, K., Bolhar, R. & Master, S. (2022) Rhizosphere competence and abiotic stress tolerance of commercially sold Pseudomonas fluorescens biofertilizers: Implications for their bioremediation potential. African Journal of Biotechnology, 21(8), 396-407.
  9. Scharf, A., Mattern, F., Bolhar, R., Callegari, I., Mattern, P. E., & Ring, U. (2022). Oligocene/early Miocene major E/W-shortening and NW-oriented sinistral slip with associated wrench-fault assemblage in the Oman Mountains related to oblique Arabia-India convergence. Authorea Preprints.
  10. Le Bras, L. Y., Milani, L., Bolhar, R. & O’Sullivan, G. (2022) Applying U-Pb chronometry and trace element geochemistry of apatite to carbonatite-phoscorite complexes–as exemplified by the 2.06 Ga Phalaborwa Complex, South Africa. South African journal of Geology, 125, 179-190. doi:10.25131/ sajg.125.0015 1
  11. Tau, M., Bolhar, R., Wilson, A. H., Anhauesser, C. R. (2022) The petrogenesis and emplacement mechanism of layered ultramafic-mafic complexes of the Barberton Greenstone Belt: Insights from the Stolzburg Complex, South Africa. South African Journal of Geology, 125, 133-166. doi.org/10.25131/sajg.125.0013
  12. Scharf, A., Bailey, C. M., Bolhar, R., Mattern, F., Ring, U. (2022). Post-obductional listwaenite formation during major regional extension in the Southeastern Oman Mountains – insights from field observations and U-Pb dating. Earth and Planetary Science Letters, 5995, 117756.
  13. Tshiningayamwe, M., Bolhar, R., Nex, P. A. M., Ueckermann, H., & Chang, Q.  (2022) An apatite trace element and Sr-Nd isotope geochemical study of syenites and carbonatite, exemplified by the Epembe alkaline‑carbonatite complex, Namibia. Lithos, 420, 106699
  14. Hofmann, A., Jodder, J., Xie, H., Bolhar, R., Whitehouse, M. and Elburg, M. (2022). The Archaean geological history of the Singhbhum Craton, India–a proposal for a consistent framework of craton evolution. Earth-Science Reviews, 228, 103994.
  15. Wilson, A., & Bolhar, R. (2022). Olivine in komatiite records origin and travel from the deep upper mantle. Geology, 50(3), 351-355.

Publications 2021

  1. Wilson, A., & Bolhar, R. (2021). Olivine in komatiite records origin and travel from the deep upper mantle. Geology.
  2. Bolhar, R. & Cawthorn, R. G.  (2021) Zircon geochronology and geochemistry of pre-Bushveld sills in the eastern Transvaal Supergroup, South Africa. South African Journal of Geology.
  3. Bolhar, R., Hofmann, A. & Allen, C. M., Maas, R. (2021). Zircon chrono-chemical signatures from the Kaapvaal Craton, South Africa: a record of magmatic crystallization, high-grade metamorphism and compositional alteration. South African Journal of Geology, 24(3), 761-782.
  4. Maghdour-Mashhour, R., Hayes, B., Pang, K. N., Bolhar, R., Shabani, A. A. T., & Elahi-Janatmakan, F. (2021). Episodic subduction initiation triggered Jurassic magmatism in the Sanandaj–Sirjan zone, Iran. Lithos, 106189.
  5. Tympel, J. F., Hergt, J. M., Maas, R., Woodhead, J. D., Greig, A., Bolhar, R., & Powell, R. (2021). Mantle-like HfNd isotope signatures in~ 3.5 Ga greenstones: No evidence for Hadean crust beneath the East Pilbara Craton. Chemical Geology, 576, 120273.
  6. Le Bras, L. Y., Bolhar, R., Bam, L., Guy, B. M., Bybee, G. M., & Nex, P. A. (2021). Three-dimensional textural investigation of sulfide mineralisation from the Loolekop carbonatite–phoscorite polyphase intrusion in the Phalaborwa Igneous Complex (South Africa), with implications for ore-forming processes. Mineralogical Magazine, 1-18.
  7. Ashwal, L. D., Ziegler, A., Glynn, S., Truebody, T., Bolhar, R. (2021). Sr-enriched glassy picrites from the Karoo Large Igneous Province are evolved, not primitive magmatic rocks. Geochemistry, Geophysics, Geosystems, 22(4), e2020GC009561.
  8. Bolhar, R., Tappe, S., Wilson, A.H., Ireland, T., Avila, J. and Anhaeusser, C. (2021). A petrochronology window into near-surface fluid-rock interaction within Archaean ultramafic-mafic crust: Insights from the 3.25 Ga Stolzburg Complex, Barberton Greenstone Belt. Chemical Geology, 120130.
  9. O’Sullivan, G.J.*, Thakurdin, Y., Bolhar, R., Horváth, P., Hoare, B.C. and Collerson, K.D., (2021) The Great Falls Tectonic Zone after the assembly of Laurentia: evidence for long-term tectonic stability from xenolith apatite. Lithos, 384-385, 105977.
  10. Maghdour-Mashhour, R., Hayes, B., Bolhar, R., Ueckermann, H. (2021). Sill Intrusion into Pyroxenitic Mush and the Development of the Lower–Upper Critical Zone Boundary of the Bushveld Complex: Implications for the Origin of Stratiform Anorthosites and Chromitites in Layered Intrusions. Journal of Petrology, 62, egaa090.