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Deutsch Intern
Institut für Geographie und Geologie

MSc Alexander Kawohl

PhD student at the Department of Geodynamics and Geomaterials Research

E-Mail: alexander.kawohl@uni-wuerzburg.de

Institute of Geography and Geology
Am Hubland
97074 Würzburg

Campus Hubland Süd
Geography building
Room 323

  • igneous petrology and geochemistry
  • ore mineralogy
  • regional geology of Ontario, Canada
  • geology of impact structures

Exploration of the Temagami Anomaly (Ontario, Canada) and its relationship to the 1.85 Ga Sudbury impact event

A detailed description of the project can be found here

This project attempts to explain the ultimate geological cause of one of the largest, hitherto unexplained, magnetic anomalies in North America, the Temagami geophysical anomaly in Ontario, Canada. The anomaly is of outstanding scientific and economic interest because it is directly adjacent to the 1.85 Ga Sudbury Complex - the second largest impact structure on Earth and one of the world’s richest mining districts thanks to widespread Ni-Cu-PGE-sulfide mineralization. The Temagami Anomaly mirrors the magnetic anomaly caused by the Sudbury Complex in terms of shape, size and intensity. Lack of outcrops and, until recently, of bore holes, prevented a proper geological understanding, and whatever genetic link with the Sudbury Complex has remained pure speculation. Preliminary petrological studies on the first deep drill hole sunk into the centre of the Temagami Anomaly revealed the presence of dioritic rocks at 2 km depth, which bear similarities with offset dykes in and around the Sudbury Complex. This raises the possibility of a genetic link with the Sudbury impact event, which if proved correct, would open up an entirely new perspective on our understanding of the Sudbury Complex and its exploration potential. Thus, the principal aim of this project is to test for such a genetic link and to provide a geological explanation for the geophysical anomaly by comparing new data on the petrology, alteration history, geochemistry, isotopic composition and geochronology to be acquired from drill core and surface samples from the area of the Temagami Anomaly with available data on the Sudbury Complex and potentially equivalent rocks in the wider region. This will include layered mafic and ultramafic intrusions, mafic dyke swarms, carbonatite stocks, and sedimentary iron formations, all of which occur in the area, bear significant economic potential, and could be possible candidates for the observed magnetic anomaly. Our preliminary observations revealed also widespread hydrothermal alteration and brecciation, whose origin and bearing on the magnetic anomaly is unclear. Thus, a further goal of the project will be to characterize this alteration and to establish its significance in terms of the cause of the Temagami Anomaly, the genesis of the Sudbury structure and the metallogeny of the area.

Education:

since 10/2018: PhD student

01/2018: M.Sc. degree, final grade 1.1

2016 - 2018: Master's student in geosciences (major geochemistry) at the University of Göttingen

06/2015: B.Sc. degree, final grade 1.3

2012 - 2015: Bachelor's student in geography and geology at the University of Würzburg

born 16th August 1993 in Schweinfurt, Germany

Main focus during studies:

Chemical volcanology (e.g. zoning of phenocrystals), fluid inclusions, analytical geochemistry (EPMA, LA-ICP MS, ID-TIMS, GC) and geochemistry of stable isotopes (esp. oxygen isotopes) as well as courses in experimental petrology, cosmochemistry, advanced mineralogy (thermodynamics & kinetics, crystal growth, crystal chemistry) and Earth history (e.g.petrological evolution of the Earth; use of stable isotopes [S, Cr] for palaeoecological issues); field trips to northeastern Bavaria and to the alkaline magmatism in the Rhön and Upper Rhine Graben (Germany and France); Bachelor thesis on the mineralogical characterization of platinum mineralization in the Bushveld Complex (South Africa).


Employment:

since 06/2019: PhD student (salary 75% E13) funded by the German Reserach Foundation DFG [Project FR 2183/12-1]

04/2018 - 05/2019: Part-time research assistant, Dept. of Geodynamics, University of Würzburg

02/2018 - 05/2018: Working student, Natural History Museum Bamberg

07/2017 - 09/2017: Student assistant, Dept. of Isotope Geology, University of Göttingen

2016 - 2018: Student assistant, Dept. of Geodynamics, University of Würzburg

10/2014 - 04/2015: Tutor, Dept. of Geodynamics, University of Würzburg

Kawohl, A., Whymark, W.E., Bite, A. and Frimmel, H.E., 2020. High-Grade Magmatic Platinum Group Element-Cu(-Ni) Sulfide Mineralization Associated with the Rathbun Offset Dike of the Sudbury Igneous Complex (Ontario, Canada). Economic Geology, in press

Kawohl, A., Frimmel, H.E., Whymark, W. and Bite, A., 2019. Rathbun Lake revisited: a magmatic-hydrothermal Pd-Pt-Cu occurrence possibly related to the Sudbury impact. Proceedings of the 15th biennial SGA meeting, Glasgow,  Volume 2, pp. 605-608.

Kawohl, A., Frimmel, H.E., Bite, A., Whymark, W. and Debaille, V., 2019. Very distant Sudbury impact dykes revealed by drilling the Temagami geophysical anomaly. Precambrian Research, 324, pp.220-235.

Kawohl, A., Frimmel, H.E., Bite, A. and Whymark, W., 2017. What’s inside the Temagami geophysical anomaly, Sudbury district, Ontario?. Proceedings of the 14th biennial SGA meeting, Quebec, Volume 4, pp.1543-1546.

Kawohl, A. and Frimmel, H.E., 2016. Isoferroplatinum-pyrrhotite-troilite intergrowth as evidence of desulfurization in the Merensky Reef at Rustenburg (western Bushveld Complex, South Africa). Mineralogical Magazine, 80(6), pp.1041-1053.

View profile on Researchgate

2019: SGA field trip grant

2018: M.Sc. degree "with distinction" (final grade 1.1/98%)

2017: Landesstipendium Niedersachsen

2017: SGA travel grant

  • Microscopes
  • Department's website
  • Radiation safety