GEOLOGICA BALCANICA, 46 (1), Sofia, July 2017, pp. 109–113.

In memoriam

Professor Nikola Angelov Jolkichev, DSc (July 16, 1925 – August 8, 2017)

One of the greatest Bulgarian palaeontologists and stratigraphers, and a long-time teacher of geology, Professor Nikola Jolkichev, DSc, passed away on Au- gust 8, 2017, at the age of 92. His colleagues, collabo- rators, and students will retain the memory of a tire- less researcher with profound knowledge of the Up- per geology of Bulgaria. During the entire time of his professional career, Prof. Jolkichev proved to be a precise worker, but also a correct and respon- sive man who was always ready for cooperation and constructive dialogue and who never hesitated to offer help and advice to his younger colleagues. Professor Nikola Jolkichev was born on July 16, 1925, in the mountain village of Chuprene (Belograd- chik area, Vidin District, NW Bulgaria), into a modest peasant family. He completed his primary education in his native village. At the age of 14, he worked as an assistant to his uncle in Sofia, where he graduated from high school. Following his first passion, music, in 1951 he successfully applied and was enrolled in the Bulgarian State Conservatoire with opera sing- ing (bass-baritone). However, one year later, on the advice of his relatives, Nikola Jolkichev applied and was admitted to Sofia University (Faculty of Biology, tivities at Sofia University and defended his DSc the- Geology and Geography), from where he graduated in sis entitled “Stratigraphy of the North European type 1957 as a geologist. In the same year, he became an Upper Cretaceous in the area of the Balkanides and Assistant Professor at the Department of Dynamic and the Moesian Platform, to the east of the Ogosta River” Historical Geology of Sofia University, where he was on May 15, 1985. In March 1973, Nikola Jolkichev successfully promoted and continued working until became an Associate Professor at the Department of his retirement in 1991. Following the advice of Acad. Dynamic and Historical Geology, and then he was Ekim Bonchev, he began studying stratigraphy and promoted to full Professor at the same department, fossils of the Upper Cretaceous sediments in Bulgaria. in February 1987. In his work and collaborations, he Along with that, Nikola Jolkichev guided students’ used freely several languages: Russian, English, Ger- practical classes of Introduction to Geology, Histori- man, and Spanish. cal Geology, and Geology of Bulgaria, as well as the Professor Jolkichev left a valuable scientific leg- basic course of Stratigraphy of Bulgaria. His PhD the- acy, having authored a monograph and authored (co- sis “Stratigraphy of the Coniacian–Maastrichtian sed- authored) about 50 research articles over a 50-year iments of the central parts of the Fore-Balkan and the period. Professor Jolkichev’s thematic focus was Moesian Platform” was defended in 1972. Soon after mainly on the stratigraphic distribution of the Upper that, Nikola Jolkichev went for three years to Cuba, Cretaceous fossils (e.g., inoceramid bivalves, ammo- where he took part of the Bulgarian geological expe- nites, belemnites, and echinoids), of which he col- dition in the province of Las Villas. Upon his return lected spectacular collections and recognized several from Cuba, he continued his research and teaching ac- new species that have been recorded in many localities

109 Field pictures of some Upper Cretaceous lithostratigraphic units of Mezdra area (West Bulgaria), established and studied by Jol- kichev (1986) (1–4): 1) The boundary between the Darmantsi and Kunino formations near Darmantsi Village; 2) The stratotype section of the Kunino Formation at Kunino Village; 3) Detail from the stratotype section of the Rumyantsevo Formation south of Rumyantsevo Village; 4) Discussion at the section near Moravitsa Village with Jaume Gallemi (Museu de ciències naturals de Barcelona) (photo: Neda Motchurova-Dekova).

around Europe ever since. He made his first steps by the presence of lower and upper Campanian strata in studying the Lower Cretaceous strata of Urgonian fa- this region. Based on the combined study of macro- cies in the area of the Cherepish Monastery (West Bul- and microfossils, he determined the boundaries and garia), but his main contributions are entirely devoted the extent of the Coniacian and the Santonian of the to the stratigraphy of the Upper Cretaceous rocks in Nikopol area and proved the presence of upper Cam- Bulgaria. Professor Jolkichev began his career with panian sediments in the Upper Cretaceous sequences systematical studies of the epicontinental Upper Cre- in front of the Stara Planina Thrust in the Central Bal- taceous deposits of the Western Srednogorie, where kan Mts. He also dated as late Campanian the rocks he recognized and described the Turonian, Santonian, of the northern limb of the Gabrovo syncline (Central Campanian, and Maastrichtian within several offi- Bulgaria) and recognized the Campanian amongst the cially introduced lithostratigraphic units. In the Upper sequences of the eastern part of the Dobrudza Basin Cretaceous outcrops of the Kondel Hill, near the town (NE Bulgaria) that had previously been thought to be of Dragoman, he discovered, in collaboration with his of Santonian age. Summarizing the observation of his graduate students, the presence of Coniacian–Santo- numerous field trips and subsequent analyses, Nikola nian sediments, which lie unconformably upon the Jolkichev gradually established 21 formal lithostrati- rocks of the . Professor Jolkichev specified graphic units (formations), which are now an integral the age of the upper Santonian sediments in the West- part of the formal lithostratigraphic scheme for the ern and Central Fore-Balkan (in Mezdra area and the Upper Cretaceous in Bulgaria. Especially significant area south of the town of Pleven) that had previously is Prof. Jolkichev’s contribution to the palaeogeogra- been assigned to the Maastrichtian and also proved phy of the land of present-day North Bulgaria during

110 the Late Cretaceous (Nikolov, 2015). For instance, he with his wide knowledge and interests. We are forever recognized that the Cenomanian marine transgression indebted to him for his unstinted guidance, friendship, took place from the east to the west in NE Bulgaria, and help. Furthermore, during his career, he main- via flooding the downgraded sectors of the Lower Cre- tained close relationships and generously shared his taceous relief. Additionally, he confirmed the data of knowledge with several foreign colleagues and stu- previous authors, according to whom the Cenomanian dents. On numerous occasions, he warmly welcomed basin in the central parts of the Moesian Platform suc- them and volunteered to serve as an experienced guide ceeded the basin. Professor Jolkichev found during field trips in Bulgaria. that the transgression of the Late Cretaceous Epicon- Nikola Jolkichev had, above all, an extremely mod- tinental Sea continuously expanded to the south, from est, honest, earnest, and very humane personality as a the late Turonian to the Maastrichtian, having a maxi- geologist, prominent scientist, colleague, and teacher. mum at the late Maastrichtian, but then followed by a We feel that he will always be alive in the memory of prominent tectonic rise that reduced the marine sedi- many of us, and we will preserve our admiration for mentation to the areas of the Lom Depression and the him as both a personality and geologist. The society Dobrudza Plateau. He recognized many regional gaps of the Bulgarian geologists extends their deepest con- in the Upper Cretaceous sequences, associated with dolences and sympathies to the family of Prof. Nikola hard grounds, which have been proved to be important Jolkichev. He will be greatly missed. Prof. Jolkichev markers and palaeogeographic indicators. will remain in the history of Bulgarian geology and in We had the chance to meet Prof. Jolkichev in the the hearts of everyone who has the privilege to have late 1990s, when he had already retired but still con- known him. tinued to come to his office in Sofia University to fol- low his rich scientific correspondence with foreign geologists and palaeontologist and to pursue the work REFERENCES on some of his last papers up to his late eighties. In the last several years, he encouraged us to work on the Nikolov, T. 2015. Prof. Nikola Jolkichev, DSc, at the age of Campanian–Maastrichtian fossil assemblages of the 90 – an uneven but dignified way of life. Review of the Bul- Mezdra area. Professor Jolkichev always impressed us garian Geological Society 76 (1), 157–159 (in Bulgarian).

Lubomir Metodiev, Docho Dochev

CONTRIBUTIONS OF PROF. NIKOLA JOLKICHEV

Jolkičev, N. 1959. Bemerkungen über das Alter der Kalk- Jolkičev, N.A. 1967. Über die Anwesenheit der Santonis- steine von der Umgebung des Klosters Čerepič. Annuaire chen Stufe im Vorbalkan zwischen den Flüssen Skăt und de l’Université de Sofia, Faculté de Biologie, Géologie et Černelka (Nordbulgarien). Bulletin of the Geological In- Géographie 53 (2), 273–277 (in Bulgarian, with German stitute, Series Geotectonics, stratigraphy and lithology 16, abstract). 187–197 (in Bulgarian, with German abstract). Jolkičev, N. 1962. Inoceramen aus dem Maastricht Bulgariens. Jolkičev, N.A., Ninov, P., Penčev, P. 1968. Über die Anwesen- Travaux sur la géologie de Bulgarie, Série Paléontologie 4, heit von Coniac- und Santonablagerungen im Kreis Drago- 133–169 (in Bulgarian, with German abstract). man. Review of the Bulgarian Geological Society 29 (3), Jolkičev, N.A. 1962. Inoceramids from the Santonian sediments 325–329 (in Bulgarian, with German abstract). of the Melovete Hill, Dimitrovgrad District (People’s Re- Jolkitschev, N., Vaptzarova, J. 1969. Über die Anwesenheit der public of Bulgaria). Vestnik Moskovskogo Universiteta 5, Campanichen Stufe im Vorbalkan zwischen dem Skăt und 30–33 (in Russian). Katunetzka Fluss. Annuaire de l’Université de Sofia, Fac- Jolkičev, N.A., Karagiuleva, Y. 1962. Stratigraphy of the Up- ulté de Géologie et Géographie 61 (1), 81–104 (in Bulgar- per Cretaceous along the “Melovete” elevation near the ian, with German abstract). town of Breznik. Travaux sur la géologie de Bulgarie, Sé- Jolkičev, N. 1970. Coniac–Santonischen Sedimente und ihre rie Stratigraphie et Tectonique 4, 117–132 (in Bulgarian, Echinidenfauna Nördlich vom Dorf Novačene, Bezirk with English abstract). Pleven. Annuaire de l’Université de Sofia, Faculté de Jolkičev, N.A. 1964. Über die Anwesenheit Campanischer Géologie et Géographie 62 (1), 73–84 (in Bulgarian, with Ablagerungen im Gebiet von Pleven. Bulletin of the Geo- German abstract). logical Institute 13, 169–179 (in Bulgarian, with German Jolkičev, N. 1971. Neue Angaben über die Stratigraphie und abstract). den Umfang der Kampan–Stufe des Schumen–Plateaus. Belmoustakov, E., Jolkičev, N. 1965. La stratigraphie du Annuaire de l’Université de Sofia, Faculté de Géologie et Maëstrichtien et du Thanetien dans le synclinal de Gabrovo Géographie 63 (1), 61–66 (in Bulgarian, with German ab- (Bulgarie du nord). Travaux sur la géologie de Bulgarie, stract). Série Stratigraphie et Tectonique 6, 177–194 (in Bulgarian, Jolkičev, N. 1971. On the presence of Upper Campanian sedi- with French abstract). ments at Beloslav Village, Varna District. Review of the

111 Bulgarian Geological Society 32 (2), 248–250 (in Bulgar- view of the Bulgarian Geological Society 47 (3), 49–61 (in ian, with English abstract). Bulgarian, with English abstract). Jolkičev, N.A. 1971. Stratigraphy of the Coniacian–Maast­ Yolkichev, N., Stoyanova-Vergilova, M. 1986. Stratigraphic ad- richtian sediments in the central part of the Fore-Balkan herence of the Upper Cretaceous Belemnitellidae in North and the Moesian Platform. PhD thesis, Sofia University Bulgaria. Annual of the Higher Institute of Mining and geo­ “St Kliment Ohridski”, 291 pp. (in Bulgarian, unpub- logy 32 (2), 25–36 (in Bulgarian, with English abstract). lished). Jolkičev, N.A.1987. Lithostratigraphic units, related to the Up- Jolkičev, N. 1978. Bohrmuschel in den Campanischen und per Cretaceous Series in the central part of the Moesian Maastrichtischen Ablagerungen zwischen den Dörfern Platform. Review of the Bulgarian Geological Society 43 Debovo und Musselievo, Kreis Pleven. Annuaire de (1), 102–112 (in Bulgarian, with English abstract). l’Université de Sofia, Faculté de Géologie et Géographie Jolkičev, N. 1987. Cretaceous System – Upper Cretaceous Se- 70 (1), 87–92 (in Bulgarian, with German abstract). ries. In: Bokov, P., Chemberski, H. (Eds), Geological con- Jolkičev, N. 1978. and Cretaceous inoceramid species ditions for hydrocarbon potential of Northeast Bulgaria. in Bulgaria. In: Pergament, M.A. (Ed.), Jurassic and Creta- Tehnika, Sofia, 91–98 (in Bulgarian). ceous inocerams and their stratigraphic importance. (Ma- Moskovski, S., Yolkichev, N. 1987. Gravity-nappe struc- terials of the IIIrd and IVth All–Union Colloquium). Acad- ture of Lozen Mountain and Vakarel ridge. Annuaire de emy of Sciences of the USSR, Order of the Red Banner of l’Université de Sofia, Faculté de Géologie et Géographie, Labor, Geological Institute, 69–76 (in Russian). 81 (1), 11–30. Jolkičev, N.A. 1980. Stratigraphie der Coniac–Maastricht–Ab- Jolkičev, N.A. 1988. Lithostratigraphic units related to the Up- lagerungen in den Zentralteilen des Vorbalkans und der per Cretaceous Series in the eastern parts of the Moesian Mösischen Platte. Annuaire de l’Université de Sofia, Fac- Platform. Review of the Bulgarian Geological Society 49 ulté de Géologie et Géographie 72 (1), 5–78 (in Bulgarian, (1), 11–25 (in Bulgarian, with English abstract). with German abstract). Jolkičev, N.A., Jovcheva, P., Dimitrova, E., Stojanova-Vergilo- Jolkičev, N. 1980. Upper Cretaceous. In: Atanasov, A. (Ed.), va, M. 1988. Stratigraphy of the Cenomanian Stage north Hydrocarbon potential of the Fore-Balkan. Tehnika, Sofia, of Pleven and new microfaunistic data on its basement. Re- 18–19 (in Bulgarian). view of the Bulgarian Geological Society 49 (2), 24–36 (in Jolkičev, N. 1981. Stratigraphy of the Upper Cretaceous in Bulgarian, with English abstract). Stara Planina granite thrust fault area (Central Stara Plan- Jolkičev, N.A. 1989. Stratigraphy of the epicontinental type ina Mountain). In: Stoyanov, S., Pironkov, P. (Eds), Fold- Upper Cretaceous in Bulgaria. “Kliment Ohridski” Uni- thrust composition of the central part of the Stara Planina versity Press, Sofia, 184 pp. (in Bulgarian, with Russian Mountain. Bulgarian Academy of Sciences. IX Problem- and English abstracts). atic International Commission of Soviet Union Academy Jolkičev, N. 1990. On “zonal” subdivision of the Upper Creta- of Sciences “Geosyncline process and the Erath core struc- ceous Series in Northeastern Bulgaria. Review of the Bul- ture”, Sofia, 57–72 (in Russian). garian Geological Society 51 (3), 105–108. Jolkičev, N., Pironkov, P. 1981. Lithostratigraphical notes of Jolkičev, N. 1993. Asparuhovo Limestone Formation; Ven- Paleogene in Kalofer part of Stara Planina Mountain. In: chan Limestone Formation; Dobrin Dol Glauconite-sandy- Stoyanov, S., Pironkov, P. (Eds), Fold-thrust composi- limestone Formation; Dobrina Sandy-limestone Formation; tion of Central part of Stara Planina Mountain. Bulgarian Darmantsi Glauconite-sandy-limestone Formation; Kay- Academy of Sciences. IX Problematic International Com- laka Limestone Formation; Kalena Bioclastic-limestone mission of Soviet Union Academy of Sciences “Geosyn- Formation; Kunino Limestone Formation; Madara Sandy- cline process and the Erath core structure”, Sofia, 73–78 limestone Formation; Mezdra Flint-limy Formation; Mog- (in Russian). ilena Flint-limestone Formation; Murna Limestone Forma- Dimitrova, E.N., Ganeva, N.T., Jolkičev, N.A., Milanova, J.N., tion; Nikopol Bioclastic-limestone Formation; Novachene Nachev, I.K. 1981. Upper Cretaceous stratigraphy in West- Marly-limestone Formation; Rumyantsevo Limestone For- ern Srednogorie. Geologica Balcanica 11 (1), 51–66. mation; Sanadinovo Marl Formation; Byalo Bardo Glauc- Jolkichev, N. 1982. Upper Cretaceous Stratigraphy in the Area onite-sandy-limestone Formation; Shumen Formation. In: of Stara Planina Granite Nappe (Central Stara Planina). Re- Tenchov, Y. (Ed.), Glossary of the formal lithostratigraph- view of the Bulgarian Geological Society 43 (1), 25–40 (in ic units in Bulgaria (1882–1992). BAS Publishing House, Bulgarian, with English abstract). Sofia, 397 pp. (in Bulgarian, with English abstract). Jolkičev, N. 1983. Upper Cretaceous. In: Atanasov, A., Bokov, Stoyanova-Vergilova, M., Jolkičev, N. 1993. Representatives P. (Eds), Geology, oil and gas perspectives of the Moesian of the genus Belemnitella of Bulgaria (Upper Cretaceous). Platform in Central North Bulgaria. Tehnika, Sofia, 38–44 Geologica Balcanica 23 (4), 25–53. (in Bulgarian). Jolkichev, N. 1998. Critical remarks on the paper Mileva- Jolkichev, N., Dimitrova, E. 1983. Campanian sediments in Ilieva, T. Gacheva, R. 1993. Additional regular echinids Varna Plateau. Review of the Bulgarian Geological Society from the Upper Cretaceous – representatives from genus 34 (1), 1–7 (in Bulgarian, with English abstract). Porosoma. Annual of the University of Mining and Geol- Jolkičev, N.A. 1984. Stratigraphy of the North European type ogy, vol. 39, part I, Geology, Sofia; 7–10. Geologica Bal- Upper Cretaceous in the area of the Balkanides and the canica 28 (1–2), 71–72. Moesian Platform to the east of the Ogosta River. Part I, Jolkichev, N.A., Naidin, D.R. 1998. The Upper Cretaceous of 179 pp.; Part II, 536 pp. DSc thesis, Sofia University “St North Bulgaria, Crimea and Mangyshlak. Article 1. Upper Kliment Ohridski” (in Bulgarian, unpublished). Cretaceous stratigraphy of North Bulgaria. Bulletin of Mos- Yolkichev, N., Moskovski, S. 1985. Olistostromes of Upper cow Society of Naturalists, Geological Series 73 (1), 17–28 Cretaceous limestones in the Lower and Middle Eocene in (in Russian, with English abstract). Provadiya Plateau. Annuaire de l’Université de Sofia “St Jolkichev, N.A., Naidin, D.P. 1999. The Upper Cretaceous of Kliment Ohridski”, Faculté de Géologie et Géographie 79 North Bulgaria, Crimea and Mangyshlak. Article 2. Cre- (1), 3–13 (in Bulgarian, with English abstract). taceous stratigraphy of South-Western Mountain Crimea. Jolkičev, N.A. 1986. Lithostratigraphic units related to the Up- Bulletin of Moscow Society of Naturalists, Geological Se- per Cretaceous in the West and Central Fore-Balkan. Re- ries 74 (5), 48–59 (in Russian, with English abstract).

112 Jolkichev, N.A., Naidin, D.P. 2000. The Upper Cretaceous of Jolkičev, N.A. 2006. The Cretaceous/Paleogene (K/Pg) bound- North Bulgaria, Crimea and Mangyshlak. Article 3. Upper ary in the Mezdra and Lyutidol syncline, Vratza District Cretaceous stratigraphy of the western part of Mountain (West-Fore Balkan, Bulgaria). Annales Géologique de la Mangyshlak. Bulletin of Moscow Society of Naturalists, Péninsule Balkanique 67, 41–49. Geological Series 75 (6), 62–75 (in Russian, with English Jolkičev, N.A. 2007. The Cretaceous/Paleogene boundary in abstract). the Eastern Fore-Balkan (Luda Kamchia Defile – locality Jolkichev, N.A. 1999. New data about the age of the Byalo bar- of Chudnite Steni). Review of the Bulgarian Geological So- do Formation in its type section. Review of the Bulgarian ciety 68 (1–3), 41–45. Geological Society 60 (1–3), 99–101 (in Bulgarian, with Jolkičev, N.A. 2009. Discussion on the lithological composi- English abstract). tion and age of the rocks from the core and limbs of the Kennedy, W.J., Jolkičev, N. 2004. Middle Cenomanian am- Lyutidol syncline, Western Fore-Balkan. Review of the Bul- monites from type section of the Sanadinovo Formation of garian Geological Society 70 (1–3), 151–164 (in Bulgarian, northern Bulgaria. Acta Geologica Polonica 54 (3), 369–380. with English abstract).

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