Position: Professor

Address: 4202 E. Fowler Ave., NES 107

Tampa FL 33620

Phone: +1-(813) 974-1067

Fax: +1-(813) 974-4808

Email: bonac@usf.edu

Specialty: Karst Geology, Cave mineralogy & Geochemistry, Quaternary paleoclimatology

Research interests: Paleoclimate and sea-level changes based on cave deposits;
Mineralogy and geochemistry of cave minerals, carbonate geology and karst protection


1999 Postdoctoral Fellow, University of Lund, Sweden (Quaternary paleoclimate)

1998 Postdoctoral Fellow, The Pennsylvania State University, USA (Paleoclimate)

1996 PhD Geology, Babes-Bolyai University, Cluj, Romania

1987 BSc Geology, Babes-Bolyai University Cluj, Romania

Recent publications

(italic = student author)

Polyak, V.J., Onac, B.P., Fornos, J.J., Hay, C., Asmerom, Y., Dorale, J.A., Gines, J., Tuccimei, P., Gines, A. 2018: A highly resolved record of relative sea level in the western Mediterranean Sea during the last interglacial period. Nature Geoscience, https://doi.org/10.1038/s41561-018-0222-5

Dumitru, O.A., Onac, B.P., Polyak, V.J., Wynn, J.G., Asmerom, Y., Fornos, J.J. 2018: Climate variability in the western Mediterranean between 121 to 67 ka derived from a Mallorcan speleothem record. Palaeogeography, Palaeoclimatology, Palaeoecology, 506: 128-138.

Cleary, D.M., Onac, B.P., Tantau, I., Wynn, J.G., Forray, F.L., Ionita, M., Tamas, T. 2018: A guano-derived d13C and d15N record of climate since the Medieval Warm Period in NW. Journal of Quaternary Science, 33 (6): 677-688.

Staubwasser, M., Dragusin, V., Onac, B.P., Assanov, S., Ersek, V., Hoffmann, D.L., Veres, D. 2018: Climate change impact on the transition of Neanderthals to modern humans in Europe. PNAS, https://doi.org/10.1073/pnas.1808647115

Dumitru, O.A., Forray, F.L., Fornos, J.J., Ersek, V., Onac, B.P. 2017: An assessment of stable isotopes variability in precipitation, cave drip, and groundwater from Mallorca Island, Western Mediterranean. Hydrological Processes, 31: 104-116; doi: 10.1002/hyp.10978

Cleary, D.M., Wynn, J.G., Ionita, M., Forray, F.L., Onac, B.P. 2017: Evidence of long-term NAO influence on East-Central Europe winter precipitation from a guano-derived δ15N record. Scientific Reports, 7, 14095

Persoiu, A., Onac, B.P., Wynn, J.G. Blaauw, M., Ionita, M., Hansson, M. 2017: Holocene winter climate variability in Central and Eastern Europe. Scientific Reports, 7: 1196 DOI:10.1038/s41598-017-01397-w

Cleary, D.M., Onac, B.P., Forray, F.L., Wynn, J.G. 2016: Controls on d15N values of cave bat guano: an assessment for reconstructing paleoclimate and environmental changes. Palaeogeography, Palaeoclimatology, Palaeoecology, 461: 87-97; http://dx.doi.org/10.1016/j.palaeo.2016.08.012

Onac, B.P., Hutchison, S.M., Geanta, A., Forray, F.L., Wynn, J.G., Giurgiu, A.C., Coroiu, I. 2015: A 2500-year Late Holocene multi-proxy record of vegetation and hydrologic changes from a cave guano-clay sequence in SW Romania. Quaternary Research, 83: 437-448; doi:10.1016/j.yqres.2015.01.007

van Hengstum, P., Richards, D., Onac, B.P., Dorale, J.A. 2015: Coastal Caves and Sinkholes In: Handbook for Sea-level Research (Shennan, I., Long, A., Horton, B., eds.), John Wiley & Sons, Oxford, p. 83-103.

Forray, F.L., Onac, B.P., Tantau, B., Wynn, J.G., Tamas, T., Coroiu, I., Giurgiu, A. 2015: A Late Holocene environmental history of a bat guano deposit from Romania: an isotopic and pollen study. Quaternary Science Reviews 127: 141-154, http://dx.doi.org/10.1016/j.quascirev.2015.05.022

Dragusin, V., Staubwasser, M., Hoffmann, D.L., Ersek, V., Onac, B.P., Veres, D. 2014: Constraining Holocene hydrological changes in the Carpathian-Balkan region using speleothem d18O and pollen-based temperature reconstructions. Climate of the Past, 10: 1363-1380; DOI:10.5194/cpd-10-381-2014

Onac, B.P., Forray, F.L., Wynn, J.G., Giurgiu, A.M. 2014: Guano-derived d13C--based paleo-hydroclimate record from Gaura cu Musca Cave, SW Romania. Environment Earth Sciences, 71 (9): 4061-4071;
DOI: 10.1007/s12665-013-2789-x

Onac, B.P., Effenberger, H.S., Wynn, J.G., Povara, I. 2013: Rapidcreekite in the sulfuric acid weathering environment of Diana Cave, Romania. American Mineralogist, 98: 1302-1309.

Onac, B.P., Wynn, J.G., Sumrall, J. 2011: Tracing the sources of cave sulfates: a unique case from Cerna Valley, Romania. Chemical Geology 288: 105-114; DOI: 10.1016/j.chemgeo.2011.07.006

Dorale, J.A., Onac, B.P., Fornos, J.J., Gines, J., Gines, A., Tuccimei, P., Peate, D.W. 2010: Sea-level highstand 81,000 years ago in Mallorca. Science, 327: 860-863.


Ponta, G.M.L. & Onac, B.P. (Eds.) 2019: Cave and karst systems of Romania. Springer Int., Cham, 544 p.

Ginés, A., Ginés, J., Gómez-Pujol, L., Onac, B.P., Fornós, J.J. (Eds.) 2012: Mallorca: a Mediterranean benchmark for Quaternary studies. Monografies de la Societat d’Història Natural de les Balears, 18, 220 p.

Racovita, G., Onac, B.P. 2000: Scarisoara Glacier Cave. Monographic study. Ed. Carpatica, Cluj-Napoca, 140 p.


2016 - 2019: A 5-million-year record of western Mediterranean Sea level variability; National Science Foundation P2C2 program (PI).

2017 - 2019: Climate and vegetation reconstruction using ice and guano cores in lava tubes at El Malpais, NM; Western National Park Association (PI)

Synergetic activities

Editor in Chief: International Journal of Speleology

President: Cave Minerals Commission (UIS)

Organizer: Sea level changes into MIS 5: from observations to predictions NSF workshop, Palma de Mallorca (April 10-14, 2012)

Research collaborations

Sea level changes based on cave deposits from Mallorca, Spain

collaboration with J. Fornos, A. Gines, J. Gines (Univ. Palma de Mallorca), J. Dorale (Univ. Iowa), P. Tuccimei (Univ. Rome 3), V. Polyak & Y. Asmerom (Univ. New Mexico), & P. Tuccimei (Univ. Rome 3).

Paleoenvironmental reconstructions based on cave bat guano

collaboration with F.L. Forray (Babes-Bolyai University, Cluj, Romania), J.G. Wynn (USF)

Mineralogy of mine caves in Sardinia, Italy

collaboration with J. De Waele, A. Naseddu, F. Sauro, P. Forti (Univ. Bologna)

Colorado River incision history of Grand Canyon from speleothems

collaboration with V. Polyak, C.A. Hill, A.N. Palmer, Y. Asmerom (UNM)

Paleoclimatic reconstructions based on ice deposits from Scarisoara Cave, Romania
collaboration with A. Persoiu (Speleo Institute Cluj),  J.G. Wynn (USF),  M. Ionita & N. Rimbu (Alfred Wegener Institute, Germany), J.A. Dorale (Univ. Iowa).

Holocene climate patterns in NW Romania based on speleothems

collaboration with V. Ersek (Northumbria University, UK) & D. Fleitmann (Univ. Reading, UK).

Created: March 23, 2008

Modified: December 9, 2018