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Dr. Igor Obreht

Research Staff


Organic Geochemistry


+49 421 218-65730



MARUM I, 2710

Igor Obreht

Re­search In­terest

  • High-resolution paleoclimate reconstruction from marine, lacustrine and eolian/loess sediments
  • Geochemistry (lipid biomarker and elemental composition)
  • Sedimentology and stratigraphy
  • Mass Spectrometry Imaging (MSI) on sediments

Education and working experiance

MARUM, University of Bremen, Germany (2018 – present)



PhD, Geosciences (2014-2017)

RWTH Aachen University, Aachen, Germany


MSc, Geography-geoecology (2012-2013)

University of Novi Sad, Faculty of Science, Novi Sad, Serbia


BSc, Geography teaching (2008-2012)

University of Novi Sad, Faculty of Science, Novi Sad, Serbia

Third par­ty fun­ding

2021-2023: Temporary positions for principal Investigators - Funding Agency: Deutsche Forschungsgemeinschaft (DFG)

Title: Micrometer-scale biomarker and elemental imaging on sediments from the northeastern Arabian Sea – reconstruction of the Indian monsoon evolution on a sub-decadal scale in the Holocene and the Bølling-Allerød interstadial



The Indian monsoon is one of the most important large-scale coupled land-ocean-atmosphere phenomena in the low latitudes. However, the forcing mechanisms of the decadal-scale monsoon variability are not well understood because knowledge of short-term climate oscillations is mostly limited to periods covered by instrumental records. Understanding of the short-scale climate evolution in the more distant past is hampered by the small number of records that preserve undisturbed signals and by methodological limitations to obtain highly resolved records. However, recent developments that interrogate laminated sediments with novel imaging techniques showed great potential to overcome these limitations. In order to reveal subdecadal-scale paleoclimate evolution of the tropics, I will apply biomarker and elemental imaging on finely laminated sediment sections from the Arabian Sea spanning the major part of Holocene (from 11.7-2 ka) and Bølling-Allerød interstadial (B-A; 14.7-12.9 ka). The goal of this project is to explore the interplay of the Intertropical Convergence Zone (ITCZ), Indian monsoon intensity and related environmental responses on the subdecadal and decadal-scale during the Holocene and B-A.

Teaching Ex­pe­ri­ence

(Co)supervised theses

Devika Varma – MSc thesis ”High-resolution multi-proxy analysis on palaeoclimatic changes in the Eastern Mediterranean during the Last Interglacial” (2019)

Janina Groninga – BSc thesis ”Hochauflösende Einblicke in die Verteilung von Lipidbiomarkern in einem bioturbierten Sedimentkern vor Mauretanien über das Mass Spectrometry Imaging“ (2019) 

Other supervision duties

Supervision of two students in month-long fieldwork in the loess region of Romania in 2016 – explaining the formation of loess and other aeolian sediments, establishing stratigraphy, teaching sampling strategy, etc.

Marit Paul - supervision of the pupil competing at the Jugend forscht – won the first place in the category „Geo- und Raumwissenschaften“ at the level of Bremen in 2019.



  1. Zeeden, C., Hambach, U., Klasen, N., Fischer, P., Schulte, P., Nett, J.J., Veres, D., Obreht, I., Chu, W., Papadopoulou, M., Viehberg, F., Schäbitz, F., Gavrilov, M.B., Marković, S.B., Vött, A., Lehmkuhl, F., 2021. Sedimentology of a Late Quaternary lacustrine record from the south-eastern Carpathian Basin. Journal of Quaternary Science. DOI: 10.1002/jqs.3297
  2. Lehmkuhl, F., Nett, J. J., Pötter, S., Schulte, P., Sprafke, T., Jary, Z., Antoine, P., Wacha, L., Wolf, D., Zerboni, A., Hošek, J., Marković, S.B., Obreht, I., Sümegi, P., Veres, D., Zeeden, C., Boemke, B., Schaubert, V., Viehweger, J., Hambach, U., 2021. Loess landscapes of Europe – Mapping, geomorphology, and zonal differentiation. Earth-Science Reviews 215, 103496. DOI:10.1016/j.earscirev.2020.103496
  3. Nett, J.J., Chu, W., Fischer, P., Hambach, U., Klasen, N., Zeeden, C., Obreht, I., Obrocki, L., Pötter, S., Gavrilov, M.B., Vött, A., Mihailović, D., Marković, S.B., Lehmkuhl, F., accepted. The early Upper Paleolithic site Crvenka-At, Serbia – the first Aurignacian lowland occupation site in the southern Carpathian Basin. Frontiers in Earth Science 9, 599986. DOI: 10.3389/feart.2021.599986
  4. Palanački Malešević, T., Dulić, T., Obreht, I., Trivunović, Z., Marković, R., Kostić, B., Važić, T., Meriluoto, J., Svirčev, Z., 2021. Cyanobacterial potential for restoration of loess surfaces through artificially induced biocrusts. Applied Sciences, 11(1), 66. DOI:10.3390/app11010066
  5. Pötter, S., Schmitz, A., Lücke, A., Schulte, P., Obreht, I., Zech, M., Wissel, H., Marković, S.B., Lehmkuhl, F., 2021. Middle to Late Pleistocene environments based on stable organic carbon and nitrogen isotopes of loess-palaeosol sequences from the Carpathian Basin. Boreas, 50(1), 184–204. DOI:10.1111/bor.12470
  6. Obreht, I., Zeeden, C., Ham­bach, U., Veres, D., Marković, S.B., Lehmkuhl, F., 2021. Reply to the discussion paper by P. Sümegi and S. Gulyás: Some notes on the interpretation and reliability of malacological proxies in paleotemperature reconstructions from loess- comments to Obreht et al.'s “A critical reevaluation of paleoclimate proxy records from loess in the Carpathian Basin”. Earth-Sci­ence Re­views, 103737. DOI: 10.1016/j.earscirev.2021.103737


  1. Obreht, I., Wörmer, L., Brauer, A., Wendt, J., Alfken, S., De Vleeschouwer, D., Elvert, M., Hin­richs, K.U., 2020. An an­nu­ally re­solved re­cord of West­ern European ve­get­a­tion re­sponse to Younger Dryas cool­ing. Qua­tern­ary Sci­ence Re­views 231, 106198. DOI:10.1016/​j.quas­cirev.2020.106198
  2. Zeeden, C., Obreht, I., Veres, D., Kaboth-Bahr, S., Hošek, J., Marković, S.B., Bösken, J., Lehmkuhl, F., Rolf, C., Ham­bach, U., 2020. Smoothed mil­len­nial-scale pa­laeo­cli­matic ref­er­ence data as un­con­ven­tional com­par­ison tar­gets: Ap­plic­a­tion to European loess re­cords. Sci­entific Re­ports 10, 5455. DOI:10.1038/​s41598-020-61528-8
  3. Avram, A., Constantin, D., Veres, D., Kelemen, S., Obreht, I., Hambach, U., Marković, S.B., Timar‐Gabor, A., 2020. Testing polymineral post-IR IRSL and quartz SAR-OSL protocols on Middle to Late Pleistocene loess at Batajnica, Serbia. Boreas, 49(3), 615–633. DOI:10.1111/bor.12442
  4. Kharbush, J. J., Close, H. G., Van Mooy, B. A. S., Arnosti, C., Smittenberg, R. H., Le Moigne, F. A. C., Mollenhauer, G., Scholz-Böttcher, B., Obreht, I., Koch, B.P., Becker, K.W., Iversen, M.H., Mohr, W., 2020. Particulate organic carbon deconstructed: Molecular and chemical composition of particulate organic carbon in the ocean. Frontiers in Marine Science, 7. DOI:10.3389/fmars.2020.00518
  5. Marković, S. B., Vandenberghe, J., Stevens, T., Mihailović, D., Gavrilov, M. B., Radaković, M. G., Zeeden, C., Obreht, I., Perić, Z.M., Nett, J.J., Lehmkuhl, F., 2020. Geomorphological evolution of the Petrovaradin Fortress Palaeolithic site (Novi Sad, Serbia). Quaternary Research, 1–14. DOI:10.1017/qua.2020.88


  1. Obreht, I., Zeeden, C., Ham­bach, U., Veres, D., Marković, S.B., Lehmkuhl, F., 2019. A crit­ical ree­valu­ation of pa­laeo­cli­mate proxy re­cords from loess in the Carpath­ian Basin. Earth-Sci­ence Re­views 190, 498-520. DOI:10.1016/​j.earscirev.2019.01.020.
  2. Bösken, J., Obreht, I., Zeeden, C., Klasen, N., Ham­bach, U., Sümegi, P., Lehmkuhl, F., 2019. High-res­ol­u­tion pa­leo­cli­matic proxy data from the MIS3/​2 trans­ition re­cor­ded in north­east­ern Hun­garian loess. Qua­tern­ary In­ter­na­tional 502, 95-107. DOI:10.1016/​j.quaint.2017.12.008
  3. Perić, Z., Ad­ophi, EL, Buylaert, JP., Stevens, T., Újvári, G., Marković, S.B., Ham­bach, U., Fisc­her, P., Zeeden, C., Schmidt, C., Schulte, P., Huayu, L., Shuang­wen, Y., Lehmkuhl, L.,Obreht, I., Veres, D., Vött, A., Zöller, L., 2019. Quartz OSL dat­ing of late qua­tern­ary Chinese and Ser­bian loess: A cross Euras­ian com­par­ison of dust mass ac­cu­mu­la­tion rates. Qua­tern­ary In­ter­na­tional 502, 30-44. DOI:10.1016/​j.quaint.2018.01.010
  4. Svirčev, Z., Dulić, T., Obreht, I., Codd, G., Lehmkuhl, F., Marković, S.B., Ham­bach, U., Meriluoto, J., 2019. Cy­anobac­teria and loess-an un­der­es­tim­ated in­ter­ac­tion. Plant and Soil, 439, 293-308. DOI:10.1007/​s11104-019-04048-3


  1. Smal­ley, I., Obreht, I., 2018. The form­a­tion of loess ground by the pro­cess of loessifica­tion: a his­tory of the concept. Geo­lo­gos 24, 163-170. DOI:10.2478/logos-2018-0015
  2. Lehmkuhl, F., Bösken, J., Hošek, J., Sprafke, T., Marković, S.B., Obreht, I., Ham­bach, U., Sümegi, P., Thiemann, A., Stef­fens, S., Lind­ner, H., Veres, D., Zeeden, C., 2018. Loess dis­tri­bu­tion and re­lated Qua­tern­ary sed­i­ments in the Carpath­ian Basin. Journal of Maps 14, 673-682. DOI:10.1080/​17445647.2018.1526720
  3. Marković, SB., Sümegi, P., Stevens, T., Schaetzl, R.J., Obreht, I., Chu, W., Buggle, B., Zech, M., Zech, R., Zeeden, C., Gav­rilov, M.B., Perić, Z., Svirčev, Z., Lehmkuhl, F., 2018. The Cr­venka loess-pa­leosol se­quence: A re­cord of con­tinu­ous grass­land dom­in­a­tion in the south­ern Carpath­ian Basin dur­ing the Late Pleis­to­cene. Pa­laeo­geo­graphy, Pa­laeo­cli­mato­logy, Pa­laeoe­co­logy 509, 33-46. DOI:10.1016/​j.pa­laeo.2018.03.019
  4. Marković, S.B., Stevens, T., Ma­son, J.A., Vanden­berghe, J., Yang, S., Veres, D., Újvári, G., Timar-Gabor, A., Zeeden, C., Guo, Z., Hao, Q., Obreht, I., Ham­bach, I., Wu, H., Gav­rilov, M.B., Rolf, C., Tomić, N., Lehmkuhl, F., 2018. Loess cor­rel­a­tions – Between myth and real­ity. Pa­laeo­geo­graphy, Pa­laeo­cli­mato­logy, Pa­laeoe­co­logy 509, 4-23. DOI:10.1016/​j.pa­laeo.2018.04.018
  5. Zeeden, C., Ham­bach, U., Veres, D., Fitz­sim­mons, K., Obreht, I., Bösken, J., Schulte, P., Lehmkuhl, F., 2018. Mil­len­nial-scale cli­mate os­cil­la­tions re­cor­ded in the Lower Danube loess: high res­ol­u­tion cor­rel­at­ive age mod­els con­strained by Cam­pan­ian Ig­n­im­brite te­phra and lu­min­es­cence dat­ing. Pa­laeo­geo­graphy, Pa­laeo­cli­mato­logy, Pa­laeoe­co­logy 509, 164-181. DOI:10.1016/​j.pa­laeo.2016.12.029
  6. Schaetzl, R.J., Bet­tis, E.A., Crouvi, O., Fitz­sim­mons, K.E., Grim­ley, D.A., Ham­bach, U., Lehmkuhl, F., Marković, S.B., Ma­son, J.A.,  Ow­czarek, P., Roberts, H.M., Rousseau, D.-D., Stevens, T., Vanden­berghe, J., Zárate, M., Veres, D., Yang, S., Zech, M., Con­roy, J.L., Dave, A.K., Faust, D., Hao, Q., Obreht, I.,Prud’homme, C., Smal­ley, I., Tri­p­aldi, A., Zeeden, C., Zech, R., 2018. Ap­proaches and chal­lenges to the study of loess—In­tro­duc­tion to the Loess­Fest Spe­cial Is­sue. Qua­tern­ary Re­search 89, 563-618. DOI:10.1017/​qua.2018.15
  7. Gav­rilov, M.B., Marković, S.B., Schaetz, R.J., Tošić, I., Zeeden, C., Obreht, I., Si­pos, G., Ru­man, A., Put­niković, S, Emunds, K., Perić, Z., Lehmkuhl., F., 2018. Pre­vail­ing sur­face winds in North­ern Ser­bia in the re­cent and past time peri­ods. Aeolian Re­search 31, 117-129. DOI:10.1016/​j.aeolia.2017.07.008
  8. Zeeden, C., Ham­bach, U., Obreht, I., Hao, Q., Abels, H., Veres, D., Lehmkuhl, F., Gav­rilov, M., Marković., 2018. Pat­terns and tim­ing of loess-pa­laeo­sol trans­itions in Eurasia: con­straints for pa­laeo­cli­mate stud­ies. Global and Plan­et­ary Change 162, 1-7. DOI:10.1016/​j.glo­placha.2017.12.021



  1. Obreht, I., Ham­bach, U., Veres, D., Zeeden, C., Bösken, J., Stevens, T., Marković, S.B., Klasen, N., Brill, D., Burow, C., Lehmkuhl, F., 2017. Shift of large-scale atmospheric sys­tems over Europe dur­ing late MIS 3 and im­plic­a­tions for Mod­ern Hu­man dis­persal. Sci­entific Re­ports 7, 5848. DOI:10.1038/​s41598-017-06285-x
  2. Bösken, J., Klasen, N., Zeeden, C., Obreht, I., Marković, S.B., Ham­bach, U., Lehmkuhl, F., 2017. New lu­min­es­cence-based geo­chrono­logy fram­ing the last two gla­cial cycles at the south­ern limit of European Pleis­to­cene loess in Stalać (Ser­bia). Geo­chrono­metria 44, 150-161. DOI:10.1515/​geo­chr-2015-0062
  3. Dulić, T., Meriluoto, J., Pa­lanački Malešević, T., Gajić, V., Važić, T., Tokodi, N., Obreht, I., Kostić, B., Kosijer, P., Khormali, F., Svirčev, Z., 2017. Cy­anobac­terial di­versity and tox­icity of bio­crusts from the Caspian Low­land loess de­pos­its, North Iran. Qua­tern­ary In­ter­na­tional 429, 74-85. DOI:10.1016/​j.quaint.2016.02.046


  1. Obreht, I., Zeeden, C., Ham­bach, U., Veres, D., Marković, S.B., Bösken, J., Svirčev, Z., Bačević, N., Gav­rilov, M.B., Lehmkuhl, F., 2016. Tra­cing the in­flu­ence of Medi­ter­ranean cli­mate on South­east Europe dur­ing the past 350,000 years. Sci­entific Re­ports 6, 36334.DOI:10.1038/​srep36334
  2. Sprafke, T., Obreht, I., 2016. Loess: Rock, sed­i­ment or soil – What is miss­ing for its defin­i­tion? Qua­tern­ary In­ter­na­tional 399, 198-207. DOI:10.1016/​j.quaint.2015.03.033
  3. Svirčev, Z., Nikolić, B., Vukić, V., Marković, S.B., Gav­rilov, M.B, Smal­ley, I., Obreht, I., Vukotić, B., Meriluoto, J., 2016. Loess and life out of Earth? Qua­tern­ary In­ter­na­tional 399, 208-217. DOI:10.1016/​j.quaint.2015.09.057


  1. Obreht, I., Zeeden, C., Schulte, P., Ham­bach, U., Eck­meier, E., Timar-Gabor, A., Lehmkuhl, F., 2015. Aeolian dy­nam­ics at the Or­lovat loess-pa­leosol se­quence, north­ern Ser­bia, based on de­tailed tex­tural and geo­chem­ical evid­ence. Aeolian Re­search 18, 69-81. DOI:10.1016/​j.aeolia.2015.06.004
  2. Važić, T., Svirčev, Z., Dulić, T., Kr­stić, K., Obreht, I., 2015. Po­ten­tial for en­ergy pro­duc­tion from reed bio­mass in the Vo­j­vod­ina re­gion (north Ser­bia). Re­new­able and Sus­tain­able En­ergy Re­views 48, 670-680. DOI:10.1016/​j.rser.2015.04.034


  1. Obreht, I., Buggle, B., Catto, N., Marković, S.B., Bösel, S., Vanden­berghe, D.A.G., Ham­bach, U., Svirčev, Z., Lehmkuhl, F., Bas­arin, B., Gav­rilov, M.B., Jović, G., 2014. The Late Pleis­to­cene Be­lot­inac sec­tion (south­ern Ser­bia) at the south­ern limit of the European loess belt: En­vir­on­mental and cli­mate re­con­struc­tion us­ing grain size and stable C and N iso­topes. Qua­tern­ary In­ter­na­tional 334-335, 10-19. DOI:10.1016/​j.quaint.2013.05.037
  2. Marković, S.B, Timar-Gabor, A., Stevens, T., Ham­bach, U., Popov, D., Tomić, N., Obreht, I., Lehmkuhl, F., Kels, H., Marković, R., Gav­rilov, M.B., 2014. En­vir­on­mental dy­nam­ics and lu­min­es­cence chro­no­logy from the Or­lovat loess-pa­laeo­sol se­quence (Vo­j­vod­ina, North­ern Ser­bia). Journal of Qua­tern­ary Sci­ence, 29, 189-199. DOI:10.1002/​jqs.2693
  3. Marković, S.B., Korać, M., Mrđić, N., Buylaert, J.P., Thiel, C., McLaren, S.J., Stevens, T., Tomić, N., Petić, N., Jovan­ović, M., Vasiljević, Dj.A., Sümegi, P., Gav­rilov, M.B., Obreht, I., 2014. Pa­laeoen­vir­on­ment and geo­con­ser­va­tion of mam­moths from the No­sak loess–pa­laeo­sol se­quence (Drmno, north­east­ern Ser­bia): Ini­tial res­ults and per­spect­ives. Qua­tern­ary In­ter­na­tional 334-335, 30-39. DOI:10.1016/​j.quaint.2013.05.047


  1. Svirčev, Z., Marković, S.B., Stevens, T., Codd, G., Smal­ley, I., Simeun­ović, J., Obreht, I., Dulić, T., Pan­telić, D., Ham­bach, U., 2013. Im­port­ance of Bio­lo­gical Loess Crusts for Loess Form­a­tion in Semi-Arid En­vir­on­ments. Qua­tern­ary In­ter­na­tional 296, 206-215. DOI:10.1016/​j.quaint.2012.10.048


  1. Kr­stić, S., Zech, W., Obreht, I., Svirčev, Z., Marković, S.B., 2012. Late Qua­tern­ary en­vir­on­mental changes in Hel­ambu Hi­mal, Cent­ral Nepal, re­cor­ded in the di­atom flora as­semblage com­pos­i­tion and geo­chem­istry of Lake Panch Pokhari. Journal of Pa­leolim­no­logy 47, 113–124. DOI:10.1007/​s10933-011-9563-4


  1. Lukić, T., Marković, S.B., Stevens, T., Vasiljević, Dj.A., Mach­alett, B., Milivo­jević, N., Bas­arin, B., Obreht, I., 2009. The loess “cave” near the Vil­lage of Surduk – An un­usual pseudokarst land­form in the loess of Vo­j­vod­ina, Ser­bia, Acta Car­so­lo­gica 38, 227-235. DOI:10.3986/​ac.v38i2-3.124