Osman Varol, PhD

Osman Varol completed his BSc [Geology] and MSc [Micropaleontology] at the University of Istanbul, Turkey. He was awarded a PhD degree [Nannofossils] by the University College London.

Osman was a member of The Stratigraphy Committee of the Geological Society of London between 1994 and 1997. He served as an External Examiner for the MSc Course in Micropaleontology at University College London between 1997 and 1999. He has occasionally been an external PhD examiner for the University of London.

Osman contributed significantly to developing and applying nannofossils through his research and publications. In the 1980s, he pioneered the industrial application of nannofossil in horizontal drilling (bio-steering) and HP/HT wells (assisting in placing the casing).

Osman has provided numerous training courses during his career, from beginner to advanced level, for oil company personnel at multiple worldwide centres that include Equinor (Statoil), Chevron, Shell, Exxon, BP and Saudi Aramco.

Osman

Publications

Varol, O. 1982. Calcareous nannofossils from the Antalya Basin, Turkey. Neues Jahrbuch für Geologie und Paläontologie, Monatshefte. 1982: 244-256

Varol, O. 1983a. Late Cretaceous - Paleocene calcareous nannofossils from the Kokaksu section Zonguldak, Northern Turkey. - Neues Jahrbuch für Geologie und Paläontologie, Abhandlungen. 1663: 431-460

Varol, O. 1983b. Proposed calcareous nannofossil zonation scheme for the Miocene to Holocene of Southeast Asia. - Bulletin Geological Society Malaysia. 16: 37-46

Varol, O. 1984. New Neogene calcareous nannofossil taxa from Malta and Southern Turkey. Neues Jahrbuch für Geologie und Paläontologie, Monatshefte. 1984: 375-384

Varol, O. 1985a. Miocene calcareous nannofossils from the Mut Basin, Southern Turkey. Journal of Micropalaeontology 42: 127-139

Varol, O. 1985b. The distribution of calcareous nannoplankton in surface sediments from the intertidal and shallow marine regimes of a marginal sea-Jason Bay, South China Sea. - Marine Micropaleontology. 9: 369-374

Hughes, G. W., Varol, O & Dunkley, P. N. 1986. Pleistocene uplift of Tetepare Island, Solomon Group, as implied by foraminiferal and calcareous nannofossil evidence. Bulletin Royal Society New Zealand 24: 397-408.

Varol, O. 1989a. Calcareous nannofossil study of the Central and Western Solomon Islands. Circum Pacific Council for Energy and Mineral Resources, Earth Science Series. 12: 239-268.

Varol, O. 1989b. Eocene calcareous nannofossils from Sile, Istanbul Northwest Turkey. Revista Espanola Micropaleontología. 213: 276-320.

Varol, O. 1989c. Palaeocene calcareous nannofossil biostratigraphy. In: Crux, J. A. & van Heck, S. E. (Eds) Nannofossils and their applications: Proceedings of the 2nd INA Conference, London 1987. British Micropalaeontological Society Publication Series. 265-310

Varol, O. 1989d. Quantitative analysis of the Arkhangelskiella cymbiformis group biostratigraphic usefulness in the North Sea Area. Journal of Micropalaeontology. 82: 131-134

Varol, O & Jakubowski, M. 1989. Some new calcareous nannofossil taxa. International Nannoplankton Association Newsletter. 11: 24-29

Al-Rifaiy, I., Varol, O & Lemone, D. 1990. Middle to upper Albian biostratigraphy of the Cuchillo Formation from Sierra de Sapello, Mexico. Newsletters on Stratigraphy. 213: 187-200

Varol, O. 1991. New Cretaceous and Tertiary calcareous nannofossils. Neues Jahrbuch für Geologie und Paläontologie, Abhandlungen. 182(1): 211-237

Hughes G. W., Varol, O. & Beydoun, Z. 1991. Evidence for Middle Oligocene rifting of the Gulf of Aden and for Late Oligocene rifting of the southern Red Sea. Marine and Petroleum Geology. 8: 354-358

Varol, O. 1992a. Revision of the Polycyclolithaceae and its contribution to Cretaceous biostratigraphy. Newsletters on Stratigraphy. 273: 93-127

Varol, O. 1992b. Sullivania, a new genus of Paleogene coccolith. Journal of Micropalaeontology. 112: 141-150

Varol, O. & Girgis, M. H. 1994. New taxa and taxonomy of some Jurassic to Cretaceous calcareous nannofossils. Neues Jahrbuch für Geologie und Paläontologie, Abhandlungen. 1922: 221-253.

Klungsoyr, T., Rafdal, J., Einchomb, C. & Varol, O. 1995. The application of an integrated method for the estimation of formation pressure in Vietnam - a case study. IADC 1995 Asia Pacific Well Control Conference, 1-11.

Varol, O. & Houghton, S. 1996. Didemnid ascidian spicules. Journal of Micropalaeontology. 15: 135-149.

Varol, O. 1998. Palaeogene. In: Bown, P. R. (Ed.) Calcareous Nannofossil Biostratigraphy. British Micropalaeontological Society Publication Series. 200-224.

Varol, O. 2004. Salisia n.g. - a new Pliocene-Pleistocene coccolith genus. Neues Jahrbuch für Geologie und Paläontologie, Monatshefte. 2004(2): 119-128

Hughes G. W., Varol O., Gill, E. & Valldeperas T. 2004. Biostratigraphy and depositional environments of Upper Cretaceous carbonates from les Collades de Basturs, southern Central Pyrenees. Cour. Forch.-Ins. Senckenberg, 247: 149-15

Varol, O. 2006. Didemnid ascidian spicules from the Arabian Peninsula. Journal of Nannofossil Research. 28(1): 35-54

Hughes, G. W., Varol, O. & Al-Khalid, M. 2008. Late Oxfordian micropalaeontology, nannopalaeontology and palaeoenvironments of Saudi Arabia. GeoArabia, 13(2): 15-46

Hughes, G. W., Al-Khalid, M. & Varol, O. 2008. Oxfordian biofacies and palaeoenvironments of Saudi Arabia. GeoArabia, 13(2): 47-60

Varol, O. 2013a. New structural observation within Coccolithus, Clausicoccus, Toweius, Prinsius and Reticulofenestra. Abstract in Geological problem solving with Microfossil III-University of Houston-March10-13, pp.110-112 Abstract

Varol, O. 2013b. Taxonomic revision of Helicosphaera and its contribution to Cenozoic biostratigraphy - Abstract in Geological problem solving with Microfossil III-University of Houston-March10-13, pp.112-114 Abstract

da Gama, R. O. B. P. & Varol, O. 2013. New Oligocene to Miocene species. Journal of Nannoplankton Research. 33(1): 1-12

da Gama, R. O. B. P. & Varol, O. 2014. A new perspective on the structure of Neogene discoasters. Journal of Nannoplankton Research 33(1): 23-28

Varol, O. & Bowman, A. R. 2019. Taxonomic revision of selected Late Jurassic (Tithonian) calcareous nannofossils and the application of mobile mounting. Neues Jahrbuch für Geologie und Paläontologie, Abhandlungen. 291/1 (2019): 65-87

Varol, O. 2019. Vonsalisia VAROL nom. nov. pro Salisia VAROL 2004 non LINDLEY 1839. Neues Jahrbuch für Geologie und Paläontologie, Abhandlungen 291/2 (2019): 229-230

Paez-Reyes. M., Carvajal-Ortiz, H., Sahoo, S. K., Varol, O., Miller, B. V., Hughes, G. W., Gaona-Narvaez, T., Patarroyo, G. D., Curtis, J. H., Lerma, I. & Copeland, P. 20021. Assessing the contribution of the La Luna Sea to the global sink of organic carbon during the Cenomanian-Turonian Oceanic Anoxic Event 2 (OAE2). Global and Planetary Change 199 (2021): 2-23.

Bowman, P. R. & Varol, O., 2021. A Taxonomic Revision of Heliolithaceae - Applications in Resolving the Problematic Calcareous Nannofossil Biostratigraphy of the Paleocene. In M. Montenari, M. (ed.). Calcareous nannofossil biostratigraphy of the Stratigraphy and timescales. 6: 43-223.

Varol, O. 2022. Denisea, a new genus of Paleocene calcareous nannofossils. Neues Jahrbuch für Geologie und Paläontologie, Abhandlungen, 304/2 (2022): 159-186.

Varol, O. & Bowman, A. R. 2022. New Middle Miocene genus OIlladiscoaster. - Abstract in International Nannoplankton Association Meeting , Avignon, France, Abstract

Varol, O., 2023. New Paleocene Calcareous Nannofossil. Carlamuelleria, Davidbukrya, Mauriceblackia, Noelia and Senelia. Marine Micropaleontology, 180: 1-41

Hughes, G. W. & Varol, O. 2024. Biostratigraphically constrained Neogene palaeoenvironments of the Red Sea rift complex. In: Rasul, N. M. A. & Steart. I. C. F. (Eds.). Rifting and Sediments in the Red Sea and Arabian Gulf Regions. 324-341

Varol, O. & Bowman, R. A. 2024. The New Middle Miocene Genus Olladiscoaster, and Related and Associated Discoasters. Grzybowski Foundation Special Publication. 28: 103 pp.

Varol, O. 2025a. A practical guide to optical studies of calcareous nannofossils. Grzybowski Foundation Special Publication.29: 222 pp.

Varol, O. 2025b. New observations on Palaeocene holococcoliths. Neues Jahrbuch für Geologie und Paläontologie, Abhandlungen