2022, Wagner, Bernd, Tauber, Paul, Francke, Alexander, Leicher, Niklas, Binnie, Steven A., Cvetkoska, Aleksandra, Jovanovska, Elena, Just, Janna, Lacey, Jack H., Levkov, Zlatko, Lindhorst, Katja, Kouli, Katerina, Krastel, Sebastian, Panagiotopoulos, Konstantinos, Ulfers, Arne, Zaova, Dušica, Donders, Timme H., Grazhdani, Andon, Koutsodendris, Andreas, Leng, Melanie J., Sadori, Laura, Scheinert, Mirko, Vogel, Hendrik, Wonik, Thomas, Zanchetta, Giovanni, Wilke, Thomas

Studies of the upper 447 m of the DEEP site sediment succession from central Lake Ohrid, Balkan Peninsula, North Macedonia and Albania provided important insights into the regional climate history and evolutionary dynamics since permanent lacustrine conditions established at 1.36 million years ago (Ma). This paper focuses on the entire 584-m-long DEEP sediment succession and a comparison to a 197-m-long sediment succession from the Pestani site ~5 km to the east in the lake, where drilling ended close to the bedrock, to unravel the earliest history of Lake Ohrid and its basin development. 26Al/10Be dating of clasts from the base of the DEEP sediment succession implies that the sedimentation in the modern basin started at c. 2 Ma. Geophysical, sedimentological and micropalaeontological data allow for chronological information to be transposed from the DEEP to the Pestani succession. Fluvial conditions, slack water conditions, peat formation and/or complete desiccation prevailed at the DEEP and Pestani sites until 1.36 and 1.21 Ma, respectively, before a larger lake extended over both sites. Activation of karst aquifers to the east probably by tectonic activity and a potential existence of neighbouring Lake Prespa supported filling of Lake Ohrid. The lake deepened gradually, with a relatively constant vertical displacement rate of ~0.2 mm a−1 between the central and the eastern lateral basin and with greater water depth presumably during interglacial periods. Although the dynamic environment characterized by local processes and the fragmentary chronology of the basal sediment successions from both sites hamper palaeoclimatic significance prior to the existence of a larger lake, the new data provide an unprecedented and detailed picture of the geodynamic evolution of the basin and lake that is Europe’s presumed oldest extant freshwater lake.

2017, Wagner, Bernd, Wilke, Thomas, Francke, Alexander, Albrecht, Christian, Baumgarten, Henrike, Bertini, Adele, Combourieu-Nebout, Nathalie, Cvetkoska, Aleksandra, D'Addabbo, Michele, Donders, Timme H., Föller, Kirstin, Giaccio, Biagio, Grazhdani, Andon, Hauffe, Torsten, Holtvoeth, Jens, Joannin, Sebastien, Jovanovska, Elena, Just, Janna, Kouli, Katerina, Koutsodendris, Andreas, Krastel, Sebastian, Lacey, Jack H., Leicher, Niklas, Leng, Melanie J., Levkov, Zlatko, Lindhorst, Katja, Masi, Alessia, Mercuri, Anna M., Nomade, Sebastien, Nowaczyk, Norbert, Panagiotopoulos, Konstantinos, Peyron, Odile, Reed, Jane M., Regattieri, Eleonora, Sadori, Laura, Sagnotti, Leonardo, Stelbrink, Björn, Sulpizio, Roberto, Tofilovska, Slavica, Torri, Paola, Vogel, Hendrik, Wagner, Thomas, Wagner-Cremer, Friederike, Wolff, George A., Wonik, Thomas, Zanchetta, Giovanni, Zhang, Xiaosen S.

This study reviews and synthesises existing information generated within the SCOPSCO (Scientific Collaboration on Past Speciation Conditions in Lake Ohrid) deep drilling project. The four main aims of the project are to infer (i) the age and origin of Lake Ohrid (Former Yugoslav Republic of Macedonia/Republic of Albania), (ii) its regional seismotectonic history, (iii) volcanic activity and climate change in the central northern Mediterranean region, and (iv) the influence of major geological events on the evolution of its endemic species. The Ohrid basin formed by transtension during the Miocene, opened during the Pliocene and Pleistocene, and the lake established de novo in the still relatively narrow valley between 1.9 and 1.3 Ma. The lake history is recorded in a 584 m long sediment sequence, which was recovered within the framework of the International Continental Scientific Drilling Program (ICDP) from the central part (DEEP site) of the lake in spring 2013. To date, 54 tephra and cryptotephra horizons have been found in the upper 460 m of this sequence. Tephrochronology and tuning biogeochemical proxy data to orbital parameters revealed that the upper 247.8 m represent the last 637 kyr. The multi-proxy data set covering these 637 kyr indicates long-term variability. Some proxies show a change from generally cooler and wetter to drier and warmer glacial and interglacial periods around 300 ka. Short-term environmental change caused, for example, by tephra deposition or the climatic impact of millennial-scale Dansgaard-Oeschger and Heinrich events are superimposed on the long-term trends. Evolutionary studies on the extant fauna indicate that Lake Ohrid was not a refugial area for regional freshwater animals. This differs from the surrounding catchment, where the mountainous setting with relatively high water availability provided a refuge for temperate and montane trees during the relatively cold and dry glacial periods. Although Lake Ohrid experienced significant environmental change over the last 637 kyr, preliminary molecular data from extant microgastropod species do not indicate significant changes in diversification rate during this period. The reasons for this constant rate remain largely unknown, but a possible lack of environmentally induced extinction events in Lake Ohrid and/or the high resilience of the ecosystems may have played a role. © Author(s) 2017.