Hans-Rudolf Wenk

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Hans-Rudolf Wenk is a Swiss mountaineer, vintner, mineralogist, crystallographer and geologist.

Education and Career[]

Wenk was born in Zürich, Switzerland in 1941 and grew up in Basel. He studied crystallography at the University of Zürich under the direction of Prof. Fritz Laves and obtained a PhD in 1965. In 1966, he went to California, first on a postdoctoral position in experimental rock deformation at UCLA with David Griggs and John Christie and then, in the fall of 1967, assuming a faculty position in mineralogy at the University of California in Berkeley.[1]

Research[]

Wenk's research interests covered a broad field of topics. His first projects consisted of crystal structure determinations of new minerals such as the silicates wenkite (named after his father, Swiss geologist  [de]), .[2] and zussmanite, and refining crystal structures from different geological settings such as lunar ilmenite,[3] carbonates and plagioclase.[4] He also used transmission electron microscopy to investigate lattice defects and microstructures of plagioclase and carbonates at high resolution.[5]

Preferred orientation of minerals in both experimentally and naturally deformed rocks remained a focus throughout his career. This involved development and application of new experimental techniques such as neutron diffraction, synchrotron X-ray diffraction and electron back-scatter diffraction. Collaboration with Fred Kocks at Los Alamos National Lab produced research projects that transformed polycrystal plasticity models to low symmetry materials and polyphase aggregates, including recrystallization.[6][7]

Further studies using diamond anvil cells to reproduce pressures, stresses and temperatures representative of the deep Earth,[8] in combination with the above-stated plasticity models, advanced the understanding of rock deformation and anisotropy in the mantle and core as observed by seismologists.[9]

Wenk combined laboratory experiments and theoretical models with fieldwork, in his teaching and research. His focus has been on the Tertiary in the Central Alps,[10][11] and Southern California mylonites[12] and pseudotachylites.[13]

His work quantifying preferred orientation and correlating crystal alignment in shales to seismic anisotropy[14] is used in seismic prospecting for oil and gas. Recent discoveries include extreme preferred orientation in slates,[15] and residual strain in quartz that can be used as a paleo-piezometer of deformed rocks.[16]

Publications[]

Wenk co-authored works on advanced mineralogy applied to broader topics such as the texture of bones,[17] identifying Hiroshima atomic bomb debris,[18] and the properties of Roman concrete.[19] His research has been reported in over 450 journal publications and 4 books[20][21]

Awards and achievements[]

Wenk's research achievements were recognized by awards, including Humboldt Fellowship,[22] Fulbright Fellowship,[23] Berndt Mathias Scholarship (Los Alamos National Lab),[24] Wason Medal of the American Concrete Institute,[25] and the Gottlob Werner Medal of the Deutsche Mineralogische Gesellschaft.

References[]

  1. ^ "Hans-Rudolf WENK". Earth and Planetary Science. Retrieved 8 June 2020.
  2. ^ Wenk, H.-R. (1974). Howieite, a new type of chain silicate, Am. Mineral., 59, 86-97
  3. ^ Raymond, K.N., Wenk, H.-R. (1971). Lunar ilmenite (refinement of the crystal structure), Contrib. Mineral. Petrol., 30, 135-340
  4. ^ Wenk, H.-R., Kroll, H. (1984). Analysis of P, I  and C plagioclase structures, Bull. Mineral, 107, 467-487
  5. ^ Wenk, H.-R., Edit. (1976). Electron Microscopy in Mineralogy, Springer-Verlag, Berlin-Heidelberg-New York, 564 pp
  6. ^ Wenk, H.-R., Canova, G., Brechet, Y., Flandin, L. (1997). A deformation-based model for recrystallization of anisotropic materials. Acta mater. 45, 3283-3296
  7. ^ Kocks, U.F., Tome, C., Wenk, H.-R. (2000). Texture and Anisotropy. Preferred Orientations in Polycrystals and Their Effect on Materials Properties. 2nd paperback edition. Cambridge University Press, 676pp
  8. ^ Wenk, H.-R., Lonardelli, I., Pehl, J., Devine, J., Prakapenka, V., Shen G., Mao H.-k. (2004). In situ observation of texture development in olivine, ringwoodite, magnesiowuestite and silicate perovskite at high pressure. Earth Planet. Sci. Lett. 226, 507-519 [doi:10.1016/j.epsl.2004.07.033]
  9. ^ Romanowicz, B., Wenk, H.-R. (2017). Anisotropy in the deep Earth. PEPI (Review paper), 269, 58-90 [doi:10.1016/j.pepi.2017.05.005]
  10. ^ Wenk, H.-R., (1973). The structure of the Bergell Alps, Eclogae Geol. Helv., 66, 255-291
  11. ^ Wenk, H.-R., S.C. Cornelius (1978). Geologischer Atlas der Schweiz, Blatt Sciora 1296 Atlasblatt 70, Schweiz. Geol. Komm. Basel
  12. ^ H.R. Wenk (1998). Deformation of mylonites in Palm Canyon, California, based on xenolith geometry. J. Struct. Geol. 20, 559-571
  13. ^ Wenk, H.-R., Johnson, L.R., Ratschbacher, L. (2000). Pseudotachylites in the eastern Peninsular ranges of California. Tectonophysics 321, 253-277
  14. ^ Wenk, H.-R., Voltolini, M., Kern, H., Popp, H., Mazurek, M. (2008). Anisotropy of Mont Terri Opalinus Clay. The Leading Edge 27, 742-748
  15. ^ Wenk, H.-R., Yu, R., Cardenes, V., Lopez-Sanchez, M.A., Sintubin, M (2020). Review: Fabric and anisotropy of slates: From classical studies to new experimental results. J. Struct. Geol.
  16. ^ Wenk, H.-R., Chandler, C.B., Chen, K., Li, Y., Tamura, N., Yu, R (2020). Residual strain in quartzites as a paleo-piezometer. Geoph. J. Int. (in press)
  17. ^ Hedegaard, C., Wenk, H.-R. (1998). Microstructure and texture patterns of mollusc shells. J. Mollusc. Studies 64, 133-136
  18. ^ Wannier, M.A., Urreiztieta, M., Wenk, H.-R., Stan, C.V., Tamura, N., Yue, B. (2019). Fallout melt debris and aerodynamically-shaped glasses in beach sands of Hiroshima Bay, Japan. Anthropocene, 25, 100196, [doi:10.1016/j.ancene.2019.100196]
  19. ^ Jackson, M.D., Landis, E.N., Brune, P.F., Vitti, M., Chen, H., Li, Q., Kunz, M., Wenk, H.-R., Monteiro, P.J.M., Ingraffea, A.R. (2014). Mechanical resilience and cementitious processes in Imperial Roman architectural mortar. Proc. Nat. Acad. Science 111, 18484-18489 [doi/10.1073/pnas.1417456111]
  20. ^ "HANS-RUDOLF WENK PUBLICATIONS". eps.berkeley.edu. Retrieved 2020-06-06.
  21. ^ Wenk, H.-R., Bulakh, A. (2016). Minerals. Their Constitution and Origin. 2nd Edn. Cambridge University Press, 621pp. ISBN 978-1-107-10626-0
  22. ^ "American Friends of the Alexander von Humboldt Foundation". www.americanfriendsofavh.org. Retrieved 2020-06-07.
  23. ^ "Hans-Rudolf Wenk | Fulbright Scholar Program". www.cies.org. Retrieved 2020-06-07.
  24. ^ Gates, Alexander E. (2009). A to Z of Earth Scientists. Infobase Publishing. ISBN 978-1-4381-0919-0.
  25. ^ "Paper Awards". www.concrete.org. Retrieved 2020-06-07.
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