Walfried Schwerdtner

Professor Emeritus
ES 2127, Department of Earth Sciences, 22 Ursula Franklin St, Toronto, ON, M5S 3B1

Campus

Fields of Study

Areas of Interest

Field-based structural geology of heterogeneously deformed orthogneisses and associated metamorphic rocks, westernmost Grenville Province (Ontario)

Since 2011, Toby Rivers, Fried Schwerdtner and Dennis Waddington have undertaken field-based litho-structural work in the southwestern Ottawa River Gneiss Complex (ORGC, Ontario portion), westernmost Grenville Province. In the summer of 2023, Dennis, Fried and a junior assistant continued their detailed study of mesoscopic vein systems observed in a variety of high-grade metamorphic rocks of the ORGC and Grenville Front Tectonic Zone (GFTZ). They focused special attention on biotite, quartz, and quartz-feldspar veins apparently due to selective mid- to upper-crustal hydrofracturing that accompanied the solid-state ductile flow of rock masses and/or the final denudation of the ORGC and GFTZ. This field work included a detailed examination of mesoscopic veins systems in clean road cuts south and southeast of Sudbury, exposing the hanging wall of the Grenville Front (see Figs. 2 and 3, below). The abstract of a virtual contribution to the 2023 Workshop of Canadian Tectonics Group (see link above) summarizes preliminary results of this work.

a geologic map with legend
Figure 1: Unpublished sketch map (Toby rivers, 2022)

 

rock outcrop with an old muffler on the top
Figure 2: Biotite veins in a highly deformed pegmatite body, hanging wall of the Wanapitei metaplutonic complex, Grenville Front Tectonic Zone (GFTZ), eastern Sudbury region.

 

a rock outcrop with a white hat used for scale
Figure 3: ‘Chaotic’ system of felsic veins (upper right corner), apparently due hydrofracturing and foliation boudinage of amphibolite. Note absence of a comparable vein system in the adjacent grey orthogneiss, pointing to selective hydrofracturing during large-scale ductile flow; French River Area, parautochthonous part of the ORGC.

 

 

 

 

   

 

 

 

 

 

 

 

 

 

 

 

 

 

 


Recent Publications

A. Research Papers in Refereed Journals

Rivers, T. and Schwerdtner, W.M. (in revision). The Ottawa River Gneiss Complex revisited, Part 1: Formation of the metamorphic core and detachment zone of a large Grenvillian metamorphic core complex. Canadian Journal of Earth Sciences.

Schwerdtner, W.M., Rivers, T., Tsolas, J., Waddington, D.H., Page, S., and Jang, J. 2016. Transtensional origin of multi-order cross-folds in a high-grade gneiss complex, south- western Grenville Province: formation during postpeak gravitational collapse. Canadian Journal of Earth Sciences, 53: 1511-1538.

Rivers, T. and Schwerdtner, W.M. 2015. Post-peak evolution of the Muskoka Domain, western Grenville Province: ductile detachment zone in a crustal-scale metamorphic core complex. Geoscience Canada, 42: 403-436.

Schwerdtner, W.M.,Rivers, T., Zeeman, B., Wang, C.C., Tsolas, J., Yang, J., and Ahmed, M. 2014. Post-convergent structures in lower parts of the 1090-1050 Ma (early Ottawan) thrust-sheet stack, Grenville Province of Ontario, southern Canadian Shield. Canadian Journal of Earth Sciences, 51 243-265

Schwerdtner, W.M. 2013. Photograph of the month. Journal of Structural Geology, 48 (October issue): 1-2.

Schwerdtner, W.M. and Yang, J.F. 2011. Photograph of the Month: Pseudotachylite at the basal contact of the Parry Sound allochthon, Grenville Province of Ontario, Canada. Journal of Structural Geology, 33: 1714.

Schwerdtner, W.M., Lu, S. J. and Yang, J.F., 2010. Wall-rock structure at the present contact surfaces between repeatedly deformed thrust sheets, Grenville Orogen of central Ontario, Canada. Canadian Journal of Earth Sciences, 47: 875-899.

Schwerdtner, W.M., Lu, S.J. and Landa, D., 2010. S/Z buckle folds as shear-sense indicators in the ductile realm: Field examples from the Grenville Province of Ontario and the Appalachians of South Carolina. In ‘From Rodinia to Pangea: The Litho- tectonic record of the Applachian Region, Geological Society of America Memoir 206, Chapter 30, p. 773-794.

Schwerdtner, W.M. and Klemens, W.P., 2008. Structure of the Ahmic domain and its vicinity, southwestern Central Gneiss Belt, Grenville Province of Ontario (Canada). Precambrian Research, 167: 16 – 34.

Schwerdtner, W.M., Riller, U.P. and Borowik, A., 2005. Structural testing of tectonic hypotheses by field-based analysis of distributed tangential shear: examples from major high-strain zones in the Grenville Province and other parts of the Canadian Shield. Canadian Journal of Earth Sciences, 42: 1927 – 1947.

Schwerdtner, W.M., Downey, M.W. and Alexander, S.A., 2004. L-S shape fabrics in the Mazinaw domain and the issue of NW-directed thrusting in the Composite Arc Belt, southeastern Ontario. Geological Society of America, Memoir 197, p. 183 – 2008.

B. Nonrefereed publications

Rivers, T. and Schwerdtner, W.M. 2014.  New ideas on the post-peak development of the Central Gneiss Belt in the Muskoka Region.  Field trip guide, Friends of the Grenville weekend in Gravenhurst, Ontario; October 3-5, 2014.

Schwerdtner, W.M., Robin, P.-Y. F., Alexander, S., Burke, J., Downey, M.W., and Serafini, G., 2003. Connection between Grenvillian deformation and granitoid pluton emplacement in the Composite arc Belt (Tweed-Kaladar area), southestern Ontario, Canada. Guidebook for Friends of the Grenville (Amis du Grenville) field trip, Department of Geology, University of Toronto.

Schwerdtner, W.M., Klemens, W.P., Robin, P.-Y. F., Vertolli. V.M., and Waddington, D.H., 2005. Geological structure and lithology in parts of the Muskoka region, southwestern Central Gneiss Belt, Grenville Province of Ontario. Field trip guide, 25th annual workshop of the Canadian Tectonics Group and Structural Geology-Tectonics Division of the Geological Association of Canada, Department of Geology, University of Toronto.

Schwerdtner, W.M., Dickin, A.P. and Robin, P.-Y. F., 2009. Rocks, structures and tectonic scenarios: Introduction to the Grenville Province of Ontario. Guidebook for a pre-sessions field trip (Geological Association of Canada), Joint Assembly (AGU- GAC-MAC Meeting), Department of Geology, University of Toronto.

 

C. Recently published Abstracts

(1) 2020 Annual GSA Meeting, Montréal QC

Carter et al. 2020. Abstract 71-12: RETROGRESSED BANDED GNEISSES AS INDICATORS OF INVERTED DUCTILE THRUSTS, WESTERN OTTAWA RIVER GNEISS COMPLEX, GRENVILLE PROVINCE OF ONTARIO). Geological Society of America Abstracts with Programs. Vol 52, No. 6, 2020; doi: 10.1130/abs/2020AM-352187 https://gsa.confex.com/gsa/2020AM/meetingapp.cgi/Paper/352187

Schwerdtner et al. 2020. doi: 10.1130/abs/2020AM-352984https://gsa.confex.com/gsa/2020AM/meetingapp.cgi/Paper/352984

2. 2021 GAC-MAC Meeting, London ON

Schwerdtner and Rivers 2021, GAC-MAC Meeting London ON, Abstracts Volume 44, p. 271, 272

Waddington and Schwerdtner 2021, GAC-MAC Meeting London ON, Abstracts Volume 44, p. 302

3. 2022 GAC-MAC Meeting, Halifax NC

Schwerdtner & Cowan 2022, GAC-MAC Meeting, Abstracts Volume 45, p. 197

4. 2023 GAC-MAC Meeting, Sudbury ON

Schwerdtner, W.M., Waddington, D.H., Liu, Lingfei and Yiu, Fannie. 2023, GAC-MAC Meeting, Sudbury ON, Abstract Volume 46

 

Education

Doctorate (Dr. Rerum Naturarum), Free University, Berlin (Germany)