The geodynamic and limnological evolution of Balkan Lake Ohrid, possibly the oldest extant lake in Europe

Abstract

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 584m-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. 26 Al/ 10 Be 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 À1 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.

Mercury records covering the past 90 kyr from lakes Prespa and Ohrid, SE Europe

“…For this study, we analysed 217 samples from between 0 and 36.27 m composite depth. We cannot entirely rule out that changes in sedimentation occurred between samples, however, recent seismic (Lindhorst et al, 2015), borehole logging (Ulfers et al, 2022) and sedimentological studies (Wagner et al, 2022 suggest that sedimentation at the DEEP site has been near-continuous since ~1.3 Ma, with no clear evidence for any major (>1-kyr)…”

“…Base image sourced from © GoogleEarth v 9.177.0.1 TM . (c) Hillshade map of the Prespa/Ohrid region and bathymetric data of lakes Prespa and Ohrid(Jovanovska et al, 2016;Wagner et al, 2022). Grey dashed lines denote watershed boundaries for lakes Prespa and Ohrid , respectively adapted from.…”

Central Mediterranean tephrochronology for the time interval 250–315 ka derived from the Fucino sediment succession

“…(2021) and Wagner et al . (2023)). B, C, D, E, F. Bi‐variate plots of compared tephra layers with SiO 2 composition >56 wt%.…”

“…2022; Wagner et al . 2023) and can now be identified as a distal Pizzo Prato equivalent based on the geochemical data from Monaco et al . (2022a).…”

Central Mediterranean tephrochronology between 313 and 366 ka: New insights from the Fucino palaeolake sediment succession

“…2017; Wagner et al . 2019, 2022). The applicability and reliability of this dating‐correlation tool depends on the completeness and the quality of the reference geochemical and geochronological dataset, which in turn requires integration of investigations of both near‐vent and distal tephra, an approach that has also proven crucial for assessing the frequency of eruptions and associated volcanic hazards (e.g.…”