Articles | Volume 13, issue 9
Biogeosciences, 13, 2757–2768, 2016

Special issue: Integrated perspectives on biological and geological dynamics...

Biogeosciences, 13, 2757–2768, 2016

Research article 11 May 2016

Research article | 11 May 2016

Aligning and synchronization of MIS5 proxy records from Lake Ohrid (FYROM) with independently dated Mediterranean archives: implications for DEEP core chronology

Giovanni Zanchetta1, Eleonora Regattieri2, Biagio Giaccio2, Bernd Wagner3, Roberto Sulpizio4, Alex Francke3, Hendrik Vogel5, Laura Sadori6, Alessia Masi6, Gaia Sinopoli6, Jack H. Lacey7,8, Melanie J. Leng7,8, and Niklas Leicher3 Giovanni Zanchetta et al.
  • 1Dipartimento di Scienze della Terra, University of Pisa, Pisa, Italy
  • 2Institute of Environmental Geology and Geoengineering, IGAG-CNR, Montelibretti, Rome, Italy
  • 3Institute of Geology and Mineralogy, University of Cologne, Cologne, Germany
  • 4Dipartimento di Scienze della Terra e Geoambientali, University of Bari, Bari, Italy
  • 5Institute of Geological Sciences & Oeschger Centre for Climate Change Research, University of Bern, Bern, Switzerland
  • 6Dipartimento di Biologia Ambientale, University of Roma “La Sapienza” Roma, Italy
  • 7Centre for Environmental Geochemistry, School of Geography, University of Nottingham, Nottingham, UK
  • 8NERC Isotope Geosciences Facilities, British Geological Survey, Keyworth, Nottingham, UK

Abstract. The DEEP site sediment sequence obtained during the ICDP SCOPSCO project at Lake Ohrid was dated using tephrostratigraphic information, cyclostratigraphy, and orbital tuning through the marine isotope stages (MIS) 15-1. Although this approach is suitable for the generation of a general chronological framework of the long succession, it is insufficient to resolve more detailed palaeoclimatological questions, such as leads and lags of climate events between marine and terrestrial records or between different regions. Here, we demonstrate how the use of different tie points can affect cyclostratigraphy and orbital tuning for the period between ca. 140 and 70 ka and how the results can be correlated with directly/indirectly radiometrically dated Mediterranean marine and continental proxy records. The alternative age model presented here shows consistent differences with that initially proposed by Francke et al. (2015) for the same interval, in particular at the level of the MIS6-5e transition. According to this new age model, different proxies from the DEEP site sediment record support an increase of temperatures between glacial to interglacial conditions, which is almost synchronous with a rapid increase in sea surface temperature observed in the western Mediterranean. The results show how a detailed study of independent chronological tie points is important to align different records and to highlight asynchronisms of climate events. Moreover, Francke et al. (2016) have incorporated the new chronology proposed for tephra OH-DP-0499 in the final DEEP age model. This has reduced substantially the chronological discrepancies between the DEEP site age model and the model proposed here for the last glacial-interglacial transition.

Short summary
Chronology is fundamental in paleoclimatology for understanding timing of events and their origin. In this paper we try to obtain a more detailed chronology for the interval comprised between ca. 140 and 70 ka for the DEEP core in Lake Ohrid using regional independently-dated archives (i.e. speleothems and/or lacustrine succession with well-dated volcanic layers). This allows to insert the DEEP chronology within a common chronological frame between different continental and marine proxy records.
Final-revised paper