J.A. JELETZKY (1915-1988): CONTRIBUTIONS TO PALAEONTOLOGY

Homage to Palaeontologist Jeletzky — many of us who have done palaeontological fieldwork or studies have huge respect for the work of Jurij Alexandrovich Jeletzky. 

Jeletzky — Jura to his family and Russian friends, and George to the international English-speaking geological community — was born in Pensa, Russia, on June 18, 1915, and died December 4, 1988. 

His father was a physician, Alexander Grigorievich Romanov, and his mother was Halina Nicolayevna (Romanova) Jeletzky.

During his high school years, which he finished in Saratov in 1932, he developed an active interest in Mesozoic stratigraphy and palaeontology while visiting the classical Upper Jurassic sections along the Volga River. 

You will undoubtedly recall that the Volga is that region that offers up the spectacular oil-in-water coloured ammonite specimens like Quenstedtoceras (Lamberticeras) lamberti, Eboraciceras, Peltoceras, Kosmoceras, Grossouvria, Proriceras, Cadoceras and Rursiceras — inspirational indeed. 

He graduated with honours from the Geological and Geophysical Faculty of the State University at Kyiv in 1938 and completed graduate studies in palaeontology and stratigraphy at the Institute of Geological Sciences of the Ukrainian Academy of Sciences, Kyiv, in 1941. His Candidate of Geological Sciences (equivalent to a PhD) thesis was devoted to the stratigraphy and belemnite fauna of the Boreal Upper Cretaceous of northern Eurasia. 

On June 22, 1941, the day Germany invaded the USSR, he married a physician, Tamara Fedorovna, the daughter of the distinguished professor F. P. Bohatirchuk and had four children together — Alex, Olga, Theodore, and Halina. 

Jurij was in Kyiv when the city fell to the German armies in September 1941, and he continued working there as a palaeontologist in the Institute of Geological Sciences of the Ukrainian Academy of Sciences, until, on the return of the Red Army in 1943, he moved his family west to Poland and Germany. He left Berlin and reached Bayreuth, Bavaria, crossing the narrow strip between the advancing lines of the Allied and Soviet armies.

Throughout those difficult years, in which he worked as a librarian and finally as a translator in the U .S.-occupied zone of Germany, Jurij managed to keep his family together and to save some of his personal belongings. In 1948, he moved to Canada, where he became a research scientist for the Geological Survey of Canada. He held that title until 1982 when he was awarded emeritus status.

Jurij’s first paper, published in 1938, dealt with Pleistocene gastropods, but the bulk of the nearly 150 papers published in his lifetime were devoted to Mesozoic palaeontology and stratigraphy, especially from western and northern Canada; Cretaceous stratigraphy and belemnite faunas of northern Eurasia; as well as palaeogeography and paleobiogeography.

He worked on Vancouver Island initially, producing geologic maps and structural and stratigraphic reports, and this work was followed up with studies of correlative strata in southern British Columbia. His second major area of study was the northern Yukon where he elucidated the stratigraphy, structure, and palaeontology of Mesozoic rocks. His outstanding contribution to the work of the Geological Survey of Canada was sustained research on the Cretaceous stratigraphy and fossils of Canada.

George was a prolific writer and made major contributions to palaeontology, particularly the study of Cretaceous ammonoids, the bivalve Buchia, and the Mesozoic coleoids, particularly belemnites on which he began his paleontological career. Indeed, George was engaged in the production of the volume on coleoids for the Treatise on Invertebrate Paleontology when he died. 

He was a great champion of the role that fossils play in biochronology and the development of the Phanerozoic time scale. George had broad interests that impacted many aspects of geology, including palaeogeography, tectonics, and eustacy.

In 1955, on completion of stratigraphic studies on Vancouver Island, Jurij began a long-range project in the Mackenzie District of northwestern Canada. He said he was searching “for the most nearly continuous and largely or entirely open-marine section of Upper Jurassic-Low er Cretaceous rocks.” 

He believed that such a section was badly needed to correlate and order sequentially what were then the scattered Early Cretaceous and Late Jurassic marine invertebrate faunas from western and Arctic Canada. His extensive field research, which began by canoe and on foot in the company of an Indigenous guide and a cook in inaccessible and unpopulated areas of the northern Yukon, was conducted between 1955 and 1975. Numerous publications and shelves of detailed field notebooks document the complete Upper Jurassic-Lower Cretaceous sequence for which he searched.

This project led to his studies on the systematics and biostratigraphy of the bivalve Buchia, used in the final synthesis of his ideas about the Jurassic/Cretaceous boundary (1984, Geological Survey of Canada Special Paper 27). That paper, he said, meant a lot to him: it summarized nearly a lifetime’s work on the Jurassic/Cretaceous boundary beds, and he intended for it to be his final word on the subject. 

In that work, as in most others related to boreal biostratigraphy, a thorough analysis of the subject was facilitated by his Russian background and his knowledge of several other Slavic languages, as well as German and French.

In the 1960s, Jurij became coordinator and principal author of the Coleoidea volume of the Treatise on Invertebrate Paleontology, after the editors had agreed that the usual compilation of the volume should be preceded by a thorough revision of morphology, taxonomy, and phylogeny. This implied the reappraisal of all principal morphologic features of the Belemnitida and included the study of all type collections available worldwide. 

Only an individual with Jurij’s determination and intellectual and working capacity could have faced such a staggering enterprise. He thus amassed an enormous amount of information and became the world’s leading authority on the subject. 

A number of papers were published, including his extensively documented work on the comparative morphology, phylogeny, and classification of the fossil Coleoidea (1966, University of Kansas Paleontological Contribution No. 7). Meanwhile, he tended to his official duties for the Survey with his habitual thoroughness. This work included the study of large collections made by other geologists, as well as provincial surveys and research by oil and mining companies, and resulted in a large number of papers and unpublished reports.

However, it slowed the preparation of the Treatise final manuscript. He could have shortened some parts and compiled others, but Jurij felt that as a conscientious scientist he could not agree to publish any results that he considered either wrong or substandard.

Thus, several papers remain unpublished, including a 331-page manuscript, finished in 1978, on early and middle Liassic Belemnite faunas of England in relation to coeval faunas of northern Eurasia.

Jurij was a Fellow of the Geological Society of America and of the Royal Society of Canada. He received the Willet G. Miller Medal of the Royal Society of Canada in 1969 for outstanding basic research in geology (palaeontology and stratigraphy), and the Elkanah Billings Medal of the Geological Association of Canada (1978) for his research on Canadian palaeontology. He was also honoured, together with Ralph Imlay of the U.S.

Geological Survey, with a Special Symposium on the Jurassic-Cretaceous biochronology and palaeogeography of North America, during the Third North American Paleontological Convention in Montreal in 1982 (see Westermann, G., ed., 1984, Geological Association of Canada Special Paper 27).

Jurij Jeletzky worked for many years to the limit of his physical endurance, although he realized the danger to his health. From 1984 until his death in 1988, suffering from cancer, he worked to the limit of his failing strength to publish an important monograph on ammonites of the boreal regions, and to finish the Coleoidea volume of the Treatise and a large synthesis on the Yukon area. 

At his death, the first paper (co-written with E. Kemper, Geological Survey of Canada Bulletin 377) was already published; Jurij was still correcting the last version of the Yukon manuscript, and the Treatise manuscript was 80 to 90 per cent complete. In the last week of his life, he forced himself to correct, in his hospital bed, the proof pages of a paper on the relation of the Neuburg Formation of Germany to the sub-boreal Volgian of the Russian platform, thus completing the circle that brought him to geology during his high school years. 

A true earth scientist, Jurij based all his interpretations and theoretical discussions on facts, and as a committed, responsible, and independent-minded researcher, he challenged any hypothesis, even the most popular one, if it did not fit his data. Thus, in 1962 (Royal Society of Canada Transactions, v. 56), he opposed the prevailing views on the Cordilleran geosyncline in relation to northern Yukon, and in 1984 (Geological Survey of Canada Special Paper 27), he rejected the existence of large-scale north-south movements of “ allochthonous terranes” in western North America and Alaska after the Middle Jurassic. 

Instead, he adhered to the expanding Earth hypothesis rather than to orthodox plate tectonics. He held that palaeontology was the only basis for practical geochronology (1956, American Association of Petroleum Geologists Bulletin, v. 40), discussed the abuse of quantification in palaeontology and biochronological correlation (1965, Journal of Paleontology, v. 39), and the overestimation of eustatic compared to vertical tectonic movements in controlling large-scale transgressions and regressions (1978, Geological Survey of Canada Paper 77-18), and he vindicated the value of molluscs with respect to foraminifers for age and depositional interpretation of Tertiary rocks in British Columbia (1973, Canadian Journal of Earth Sciences, v. 10). 

He also thought that his data from extensive collections of Late Jurassic-Early Cretaceous Buchia and Late Cretaceous Inoceramus were in conflict with the “punctuated equilibrium” hypothesis. Whenever he became involved in scientific controversy, it was based on his deep belief that a scientist’s duty is to express openly his doubts whenever his data are challenged. Thus, he was always ready to stand up for his beliefs without being pompous; on the contrary, he was a very modest man.

Jurij never refused to give advice, when asked, especially to a junior colleague, or to write a detailed review of a thesis or manuscript. Even in the last weeks of his life, he completed a review, knowing that time was short and precious. He was extremely loyal to his profession—his love—and to the institution for which he worked.

He loved life, every hour of it. In his private life, he was a kind and generous person, always ready to give help to a colleague or friend. He never showed the strains of a personal life full of hardships.

Jura (George) Jeletzky will be missed by all those who believe that personal freedom, independence of thought, respect for facts, and a straightforward attitude in upholding fundamental principles as the hallmarks of a valuable human and scientific life.

A.C. Riccardi, Museum de Ciencias Naturalas, Universidad Nactional de La Plata, Argentina wrote a wonderful memorial to Jeletzky as did Godfrey Nowland, Chief Paleontologist, Geological Survey of Canada. Much of what they shared is included here. 

https://www.cambridge.org/core/services/aop-cambridge-core/content/view/BF4C5A14713639CE54B473408D4406E6/S0022336000019776a.pdf/div-class-title-j-a-jeletzky-1915-1988-div.pdf