Portal de Periódicos da CAPES

Victor Lyudvigovich Masaitis (July 21, 1927–July 21, 2019)

2019; Wiley; Volume: 54; Issue: 11 Linguagem: Inglês

10.1111/maps.13394

1945-5100

M. V. Naumov, B. A. Ivanov, A. Deutsch, F. Langenhorst,

Geological and Geochemical Analysis

Dr. Victor Ludvigovich Masaitis, an outstanding Russian geologist, initiator of research of impact structures in the former Soviet Union (USSR), discoverer of the giant deposits of impact diamonds in the Popigai impact structure, fellow and awardee of the Barringer Medal of the Meteoritical Society, passed away on July 21, 2019, at the age of 92. Victor Masaitis was born on July 21, 1927 in Leningrad to Lithuanian parents. In 1950, Victor graduated from the Mining Institute in Leningrad (now the Saint Petersburg Mining University, Russian Federation1). Victor served most of his professional career as an employee of the A.P. Karpinsky All-Russian Geological Research Institute (VSEGEI, Leningrad, Sankt-Petersburg), and started his professional life as a geologist in East Siberia, prospecting for just found Siberian diamonds. Until 1970, Victor was involved mainly in complex investigations of magmatic rocks in East Siberia. These investigations proved Victor Masaitis as a prominent and very successful expert in geology, tectonics, and magmatic associations of the Siberian platform and surrounding mobile belts. Victor's achievements in this research area include revealing of the first differentiated trap intrusion in the Vilyui River basin, distinguishing (previously unknown) mafic formations older than the typical Early Triassic Siberian flood basalts, and substantiation of an evolutionary model of the magmatic activity in the Siberian platform. These results were compiled by Victor Masaitis in two dissertations: “Petrology of the Alamdjakh intrusive” (1956) and “Pre-Permian basic magmatism in the Siberian Platform” (1970). Victor Masaitis was a notably excellent field geologist and prospector; in total, he carried out expeditions in more than 30 field seasons in wild regions of Siberia that had not been geologically explored before. Later, Victor remembered: “I still got the most vivid expressions from my geological routes through the Siberian taiga. Many hundreds of kilometers on foot, on deer, and rafts or rubber boats remained for ever in my memory.” From 1958–1962, Victor Masaitis was the chief scientist of the Soviet-North Korean geological expedition, which discovered for the first time uranium ore deposits in the region and compiled a geological map of North Korea. After return to the USSR, he continued to study mafic formations in Jakutia, especially the newly discovered Viljuy-Patom basalt province, which turned out to be older than Siberian traps. When summarizing his studies on Siberian magmatic rocks, Victor Masaitis paid attention to a specific “volcanic” feature, which did not fall into the established consistency of magmatic formation distribution. This was the Popigai circular structure. As Victor explains in his memoirs, the first ideas about the impact nature of Popigai originated while he read papers about the Ries, Germany (Shoemaker and Chao 1961; Engelhardt et al. 1967a, 1967b), and Canadian impact craters (Beals et al. 1963; Dence 1965). He also mentioned the “Green Bible” (French and Short 1968) as source of primary knowledge. During the very first field trip to Popigai in 1970, Victor and his colleagues found shatter cones, suevites, massive impact melt sheets (known from literature to occur in impact structures). Processing of Popigai impact breccias in the thin section lab revealed in situ diamonds, hence substantiating the impact origin of diamonds. In a single field season, the VSEGEI team found most of the well-known evidence of a giant impact structure (with a diameter of about 90–100 km), and impact diamonds. Atypical diamonds had been previously reported far outside the crater in placer deposits of rivers, but they were misinterpreted as carbonados, suggesting a mantle origin. Victor's direct observation of diamonds in impact breccias and X-ray evidence for the existence of lonsdaleite proved both the impact nature of the diamonds and of the Popigai structure. However, many Soviet (later—Russian) geologists did not believe in Victor's interpretation and continued to publish endogenic explanations of Popigai until the last decade. The first publication about Popigai in a Russian journal (Masaitis et al. 1972) was also the last for a long time, as Popigai diamonds have been classified as a potential strategic deposit. Under the scientific leadership of Victor Masaitis, extensive fieldwork was carried out in and around the impact structure in 1972–1981. This work included mapping; prospecting; geophysical surveys; drilling; and detailed petrographic, geochemical, and mineralogical studies. The latter as well as mapping and geological logging of boreholes, was performed by a special research group, founded in 1974 within the Petrology Department of VSEGEI. These works resulted in the discovery of some primary and placer deposits of impact diamonds, including the giant (~150 billions of carats) Skalnoye deposit. Victor Masaitis was awarded as the discoverer of these deposits. For about 10 years, Soviet authorities tested mining and extraction of impact diamonds on an industrial scale, but this new material did not find commercial demand in Soviet industries. The mining project was suspended; as a consequence, in 1998, Victor and his colleagues published a book comprising the main results of the Popigai diamonds in Russian (the English version is—Masaitis [2019]—was published just a few weeks before his passing in July). From the very beginning in the “impact” stage of his career, Victor also paid attention to other enigmatic “volcanic” structures on the USSR territory. This was the beginning of the exploration of many other impact structures in the USSR by the VSEGEI impact research group, led by Victor. The greatest research projects were carried out at the Kara (1976–1979) and Puchezh-Katunki (1988–1992) impact structures. Other projects provided evidence of impact origin for the Kaluga, Kursk, Mishina Gora, Karla, Boltysh, and Ilyintsy structures. Victor Masaitis was the leader of all these projects, and editor and leading author of books, in which principal results were summarized (Masaitis et al. 1975, 1980; Masaitis 1990, 1998, 1999). Many of these books were translated into English. His last book, Geology and Origin of the Puchezh-Katunki Impact Structure, is scheduled for publication at the end of this year. In addition, Victor Masaitis is the author of more than 150 articles, concerning classification and nomenclature of impact-generated and shock-metamorphosed rocks; geology, petrology, and mineralogy of different impact structures; modeling of impact cratering; economics of impact structures; impact diamonds; among others. After 1989, Victor Masaitis took an active part in international activities on impact crater research. For the next 30 years, he presented a lot of articles and reports on impact workshop conferences and made a great contribution to our knowledge on impact cratering. In particular, revealing of impact diamonds in some terrestrial craters (Ries, Lappajärvi, Sudbury) happened with his direct assistance. For example, in his article on impact diamonds from the Ries and Popigai craters (Masaitis 1994), he not only confirmed the early find of Ries diamonds (Rost et al. 1978) but also used the term “apographitic” (Greek “after graphite”) impact diamonds to indicate their solid-state formation from graphite contained in crystalline basement rocks of these craters. At the same time, an alternative formation mechanism of impact diamonds was proposed by vapor deposition of carbon from dissociated carbonates (Hough et al. 1995). This hypothesis was based on the find of some Ries diamonds, which were intergrown with moissanite, a template phase for industrial vapor growth of diamonds. Astonishingly, Victor's investigations on Lappajärvi diamonds provided further evidence for the solid-state formation of impact diamonds and provided an explanation for the existence of moissanite, which forms when impact diamonds are embedded in hot silica-rich impact melt and react to form silicon carbide via the so-called Acheson process (Langenhorst et al. 1999; Masaitis et al. 1999). Another little recognized achievement of Victor was the discovery of impact diamonds in suevites of the black member Onaping formation from Sudbury (Masaitis et al. 1999). These diamonds are morphologically and internally different from the Ries and Popigai diamonds, indicating that the precursor carbon material in the crystalline basement rocks of Sudbury possesses a different degree of order. Victor visited many impact structures in Europe, North America, South Africa, and Australia. As a result, he gathered a vast collection of samples from more than 40 impact structures, a portion of which is held now in the Geological Museum in VSEGEI. In 1991, the Meteoritical Society awarded him with the precious Barringer Medal. In his Barringer Medal Address, Victor pointed out that “Terrestrial impact craters are important geological and geomorphological objects that are significant not only for scientific research but for industrial and commercial purposes.” The citation of Victor Masaitis's enormous contribution to “impact science” was published in Meteoritics 27, 19–20 (1992) by another hero of the still “young” impact science, Robert “Bob” Dietz. He emphasized that the discoveries and publications of Victor contributed substantially in the Eastern world to the (slow) acceptance of a new geologic paradigm, that is, the importance of terrestrial bolide impacts for the evolution of our Earth, especially during the earth's first billion years. Victor soon became a good friend with Colonel Paul Barringer and his late wife Dorothy. At this time, a group of impact researchers from Sweden (Maurits Lindström, Herbert Henkel), Finland (Lauri Pesonen), Germany (Alex Deutsch), and France (Urs Schärer) started to establish a forum for the small group of impact scientists in Europe, this process ended successfully in a network, founded by the European Science Foundation (ESF). Victor was installed as “observer” together with Richard Grieve, and Jay Melosh; the ESF-Network brought scientists and young students from all over Europe together, resulting in common projects and publications. It was the time when the new geological paradigm impact (K-T boundary, death of the dinosaurs) was discussed very controversially. Within the frame of this project, later promoted as ESF research program (RESPONSE OF THE EARTH SYSTEM TO IMPACT PROCESSES (IMPACT) [1998–2003]), Victor, and a great number of students and scientists, visited craters, outcrops at ejecta deposits, as well as research institutes (e.g., AWI Bremerhaven). Victor was teaching at ESF summer schools, and shared his deep knowledge of the geology of impact structures with all interested people. He was invited several times by the German Science Foundation (DFG) to stay as visiting scientist at the Institute for Planetology, University of Muenster, where he helped to guide and supervise a PhD work (Bianca Kettrup). He also was deeply involved in the PhD work of Johanna Salminen (University of Helsinki, supervised by Lauri Pesonen). A highlight in his later years was the legendary geological excursion IPEX to the Popigai impact structure in 1997 with a small group of scientists from Russia, Germany, and Canada (among those the authors of this obituary). Legendary, because the worst crisis in the history of Russia after the end of the Soviet regime, caused supply at a rather low level—but six of the expedition members were the first “Western” visitors of this geological wonderland. Thank you, Victor! He was walking up to 40 km a day in the partly marsh landscape in order to show and explain the overwhelmingly spectacular outcrops. Two articles in popular scientific journals (Episodes, Forschung) informed the general public for the first time about this fantastic impact structure, and their extraordinary outcrops. Although Victor Masaitis is known in the meteoritics community for his pioneering work in exploration of impact structures in former Soviet Union, his part in Russian geology was much wider. During most of his geological activity, Victor Masaitis was a prominent researcher in petrology of igneous and volcanic rocks. From 1971 to 1984 and then from 1989 to 2009, he headed the Petrology Department of VSEGEI, which was the main authority in magmatic petrology in USSR; this was in many respects due to Victor's efforts. Among scientific works edited by Victor Masaitis are fundamental papers such as “Magmatic associations of USSR” (1979), “Atlas of Paleovolcanological Maps of Northeastern Eurasia” (2000), “Russian Glossary of Geology” (2010–2012). For more than 25 years Victor was an editor of the journal Regional Geology and Metallogeny. Victor was a friend, a wonderful warm and kind person, very trustful, and always willing to help; he was an innovator and a highly qualified scientist with outstanding field experience (citing Lauri Pesonen: jumping like a school boy over rocks in the islands of Jänisjärvi at age of 75). Victor Masaitis met his wife, Tatjana Selivanovskaya, due to teamwork in Siberia. In 2015, they celebrated their golden wedding. Tatjana, a highly qualified petrographer, was a faithful partner for Victor during his geological research including studies of different impact craters. Their senior son, George, is a geologist, while the junior son, Velislav, is working in nature conservation projects. Victor Lyudvigovich Masaitis exemplifies a practical geologist and a scientist who devoted his life to the study of our planet. From personal communications with him, each of us found understanding and wisdom, felt support, and got solutions of many difficult problems. The memory of Victor will forever be preserved by us. Deutsch A., Masaitis V. L., Langenhorst F., and Grieve R. A. F. 2000. Popigai, Siberia—Well preserved giant impact structure, national treasury, and world's geological heritage. Episodes 23:3–11. Grieve R. A. F. and Masaitis V. L. 1994. The economic potential of terrestrial impact craters. International Geology Review 36:105–151. Masaitis V. L. ed. 1983. Textures and structures of impact breccias and impactites (in Russian). Leningrad: Nauka Press. 159 pp. Masaitis V. L. 1989. The economic geology of impact craters. International Geology Review 31:922–933. Masaitis V. L. (ed.). 1990. Impact craters on the MZ-CZ boundary (in Russian). Leningrad: Nauka Press. 190 pp. Masaitis V. L. 1992. Impact craters: Are they useful? The Barringer Medal Address. Meteoritics 27:21–27. Masaitis V. L. 1994. Impactites of the Popigai impact crater. In Large meteorites and planetary evolution, edited by Dressler B. O., Grieve R. A. F., and Sharpton V. L. Geological Society of America Special Paper 293, Boulder Colorado. Geological Society of America. pp. 153–162. Masaitis V. L. 1998. Popigai crater: Origin and distribution of diamond-bearing impactites. Meteoritics & Planetary Science 33:349–359. Masaitis V. L. 1999. Impact structures of northeastern Eurasia: The territories of Russia and adjacent countries. Meteoritics & Planetary Science 34:691–711. Masaitis V. L. 2003. Obscure-bedded Ejecta facies from the popigai impact structure, Siberia: Lithological features and mode of origin. In Impact markers in the stratigraphic record, edited by Koeberl C. and Martinez-Ruiz F. C. Berlin Heidelberg: Springer-Verlag. pp. 137–162. Masaitis V. L. 2005a. Redistribution of lithologies in impact-induced dikes of impact structures. In Impact tectonics, edited by Koeberl C. and Henkel H. Berlin Heidelberg/New York: Springer. pp. 111–130. Masaitis V. L. 2005b. Morphological, structural and lithological records of terrestrial impacts: An overview. Australian Journal of Earth Sciences 52:509–528. https://doi.org/10.1080/08120090500170427. Masaitis V. L. 2006. Review of the Barringer crater studies and views on the crater's origin. Solar System Research 40:500–512. Masaitis V. L. 2013. Impact diamonds of the Popigai astrobleme: Main properties and practical use. Geology of Ore Deposits 55:607–612. Masaitis V. L., ed. 2019. Popigai impact structure and its diamond-bearing rocks. Berlin: Springer Verlag. 205 pp. https://doi.org/10.1007/978-3-319-77988-1. Masaitis V. L. and Naumov M. V. eds. 2019. The geology and origin of the Puchezh-Katunki impact structure. Berlin:Springer Verlag (in press). Masaitis V. L. and Pevzner L. A. eds. 1999. Deep drilling in the Puchezh-Katunki impact structure (in Russian). St. Petersburg: Springer. 392 pp. Masaitis V. L., Futergendler S. I., and Gnevushev M. A. 1972. Diamonds in impactites of the popigai meteorite crater. (in Russian). Proceedings of Russian Mineralogical Society (Zapiski VMO) 101:108-113. Masaitis V. L., Mikhailov M. V., and Selivanovskaya T. V. 1975. Popigai meteorite crater (in Russian). Nauka Press: Moscow, 124 p. Masaitis V. L., Mashchak M. S., Selivanovskaya T. V., Kirichenko V. T., and Danilin A. N. 1978. Geological Map of the Popigai Meteorite Crater of 1:200 000 scale (in Russian). Leningrad: VSEGEI Press. Masaitis V. L., Danilin A. N., Mashchak M. S., Raikhlin A. I., Selivanovskaya T. V., and Shadenkov E. M. 1980. Geology of astroblemes (in Russian). Leningrad: Nedra Press. 231 p. Masaitis V. L., Mashchak M. S., Raikhlin A. I., Selivanovskaya T. V., and Shafranovsky G. I. 1998. Diamond-bearing impactites of the Popigai astrobleme (in Russian). VSEGEI Press: St. Petersburg, SPb. 178 pp. Masaitis V. L., Shafranovsky G. I., Grieve R. A. F., Langenhorst F., Peredery W. V., Therriault A. M., Balmasov E. L., and Fedorova I. G. 1999. Impact diamonds in the Suevitic breccias of the black member of the Onaping formation, Sudbury structure, Ontario, Canada. In Large meteorite impacts and planetary evolution II, edited by Dressler D. and Sharpton V. Special Paper of the Geological Society of America. Boulder, Colorado: Geological Society of America. 317–321. Masaitis V. L., Pilkington M., Pesonen L. J., and Grieve R. A. F. 2002. Geophysics and Petrophysics of the Popigai Impact Structure, Siberia. In Impacts in Precambrian shields, edited by Plado J., and Pesonen L. J. Berlin Heidelberg: Springer-Verlag. pp. 87–108. ISBN 978-3-642-07803-3.