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, Berkeley.

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 Eduard Wenk), howieite.Wenk, H.-R. (1974). Howieite, a new type of chain silicate, Am. Mineral., 59, 86-97 and zussmanite, and refining crystal structures from different geological settings such as lunar ilmenite,Raymond, K.N., Wenk, H.-R. (1971). Lunar ilmenite (refinement of the crystal structure), Contrib. Mineral. Petrol., 30, 135-340 carbonates and plagioclase.Wenk, H.-R., Kroll, H. (1984). Analysis of P, I  and C plagioclase structures, Bull. Mineral, 107, 467-487 He also used transmission electron microscopy to investigate lattice defects and microstructures of plagioclase and carbonates at high resolution.Wenk, H.-R., Edit. (1976). Electron Microscopy in Mineralogy, Springer-Verlag, Berlin-Heidelberg-New York, 564 pp

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.Wenk, H.-R., Canova, G., Brechet, Y., Flandin, L. (1997). A deformation-based model for recrystallization of anisotropic materials. Acta mater. 45, 3283-3296Kocks, 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

Further studies using diamond anvil cells to reproduce pressures, stresses and temperatures representative of the deep Earth,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] 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.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]

Wenk combined laboratory experiments and theoretical models with fieldwork, in his teaching and research. His focus has been on the Tertiary Bergell pluton in the Central Alps,Wenk, H.-R., (1973). The structure of the Bergell Alps, Eclogae Geol. Helv., 66, 255-291Wenk, H.-R., S.C. Cornelius (1978). Geologischer Atlas der Schweiz, Blatt Sciora 1296 Atlasblatt 70, Schweiz. Geol. Komm. Basel and Southern California mylonitesH.R. Wenk (1998). Deformation of mylonites in Palm Canyon, California, based on xenolith geometry. J. Struct. Geol. 20, 559-571 and pseudotachylites.Wenk, H.-R., Johnson, L.R., Ratschbacher, L. (2000). Pseudotachylites in the eastern Peninsular ranges of California. Tectonophysics 321, 253-277

His work quantifying preferred orientation and correlating crystal alignment in shales to seismic anisotropyWenk, H.-R., Voltolini, M., Kern, H., Popp, H., Mazurek, M. (2008). Anisotropy of Mont Terri Opalinus Clay. The Leading Edge 27, 742-748 is used in seismic prospecting for oil and gas. Recent discoveries include extreme preferred orientation in slates,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. and residual strain in quartz that can be used as a paleo-piezometer of deformed rocks.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)

Publications Wenk co-authored works on advanced mineralogy applied to broader topics such as the texture of bones,Hedegaard, C., Wenk, H.-R. (1998). Microstructure and texture patterns of mollusc shells. J. Mollusc. Studies 64, 133-136 identifying Hiroshima atomic bomb debris,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] and the properties of Roman concrete.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. Natl. Acad. Sci. 111, 18484-18489 [doi/10.1073/pnas.1417456111] His research has been reported in over 450 journal publications and 4 booksWenk, H.-R., Bulakh, A. (2016). Minerals. Their Constitution and Origin. 2nd Edn. Cambridge University Press, 621pp.

Awards and achievements Wenk's research achievements were recognized by awards, including Humboldt Fellowship, Fulbright Fellowship, Berndt Mathias Scholarship (Los Alamos National Lab), Wason Medal of the American Concrete Institute, and the Gottlob Werner Medal of the Deutsche Mineralogische Gesellschaft. His fieldwork was inspired by his passion for mountains where he climbed Mont Blanc, Piz Badile, Finsteraarhorn, Half Dome, Mt. Shasta, Kilimanjaro, Fujiyama, Kinabalu, and Pico di Orizaba.

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