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Lake Ohrid (FYROM, Albania) is thought to be more than 1.2 million years old and hosts more than 200 endemic species. As a target of the International Continental Scientific Drilling Program (ICDP), a successful deep drilling campaign was carried out within the scope of the Scientific Collaboration on Past Speciation Conditions in Lake Ohrid (SCOPSCO) project in 2013. Here, we present lithological, sedimentological, and (bio-)geochemical data from the upper 247.8 m of the overall 569 m long DEEP site sediment succession from the central part of the lake. According to an age model, which is based on nine tephra layers (1st order tie points), and on tuning of biogeochemical proxy data to orbital parameters (2nd order tie points) and to the global benthic isotope stack LR04 (3rd order tie points), respectively, the analyzed sediment sequence covers the last 640 ka. The DEEP site sediment succession consists of hemipelagic sediments, which are interspersed by several tephra layers and infrequent, thin (< 5 cm) mass wasting deposits. The hemipelagic sediments can be classified into three different lithotypes. Lithotype 1 and 2 deposits comprise calcareous and slightly calcareous silty clay and are predominantly attributed to interglacial periods with high primary productivity in the lake during summer and reduced mixing during winter. The data suggest that high ion and nutrient concentrations in the lake water promoted calcite precipitation and diatom growth in the epilmnion in during MIS15, 13, and 5. Following a strong primary productivity, highest interglacial temperatures can be reported for MIS11 and 5, whereas MIS15, 13, 9, and 7 were comparable cooler. Lithotype 3 deposits consist of clastic, silty clayey material and predominantly represent glacial periods with low primary productivity during summer and longer and intensified mixing during winter. The data imply that most severe glacial conditions at Lake Ohrid persisted during MIS16, 12, 10, and 6 whereas somewhat warmer temperatures can be inferred for MIS14, 8, 4, and 3. Interglacial-like conditions occurred during parts of MIS14, and 8.

We report the gamma ray fluctuations from downhole logging data obtained in the sediments of Lake Ohrid from 0 to 240 m below lake floor. These variations in gamma ray and potassium values strongly correlate with fluctuations in global δ18O values and can be thus considered a reliable proxy to depict glacial–interglacial cycles, with high clastic input during cold and/or drier periods and high carbonate precipitation during the warm and/or humid periods in Lake Ohrid. Spectral analysis (sliding window) was applied to investigate the climate signal and their evolution over the length of the borehole. Linking the downhole logging data with orbital cycles was used to estimate sedimentation rates, which shift from 45 cm ka−1 between 0 to 110 m to 30 cm ka−1 from 110 to 240 m below lake floor. The effect of compaction was compensated for. Sedimentation rates increase on average by 14% after decompaction of the sediment layers. Tuning of minima and maxima in gamma ray and potassium values vs. LR04 minima and maxima, in combination with eight independent tephrostratigraphical tie points, allows the establishment of a robust age model for the downhole logging data over the past 630 ka in Lake Ohrid.

The MAGSAT map for Europe shows two significant sign-reversed magnetic anomalies. The negative one is located over Palaeozoic crust, whereas the positive one is over Precambrian crust. As an alternative to a previously published interpretation a three-dimensional model body is presented situated only over Palaeozoic crust showing a magnetization of constant Permian direction but reversed polarity. Varying magnetization intensities are associated with different parts of the body. The predominant remanent magnetization requires a Q ratio clearly above 1. The possible carriers of the magnetization could be pyrrhotite and fine-dispersed magnetite.

The magnetic anomalies represented on our map of Central Europe reflect the geological units and these anomalies are tentatively correlated with known geological structures. In Scandinavia strong magnetic anomalies caused by crystalline rocks of the East European Platform have been observed. Their southern boundary corresponds to the Elbe Line, the border between the mobile part of the East European Platform and the Dutch-German Platform. Here only some broader anomalies can be found and are caused by a magnetic basement (magnetization M = 2 A/m) under a 12–15 km thick layer of sediments. A southern margin of the Dutch-German Platform can be assumed along the W-E “Northern German Line” which is marked by local magnetic anomalies. Younger magmatic events are presumed to be the sources of these anomalies. The Rhenohercynian is located south of the Dutch-German Platform. Small NE-striking anomalies indicate a weak magnetic basement (M = 0.35 A/m). A magnetic relief varying between 9 and 15 km is obtained by relief calculations. West of the Rhenohercynian anomalies of relatively strong amplitudes prevail. These correspond to the Brabant Massif, the eastern boundary of which presumably influences the tectonically controlled anomalies of Erkelenz and Lingen. There is no magnetic indication of a continuation of the Brabant Massif into the Rhenohercynian. The Mid-German Crystalline Rise and the Saxothuringian zone of the Variscan belt are situated south of the Rhenohercynian. Both areas show strong magnetic anomalies. The southwestern border forms an arch around the Brabant Massif and ends at the Paris Basin Anomaly. This magnetic zone finds its equivalent in a magnetic belt, the Donau Anomaly, which can be followed to the Massif Central in the southwest. This is located in the middle of the Moldanubian, which is characterized by a relatively undisturbed magnetic field. The strong anomalies in the Saxothuringian and Donau magnetic belts point to an accumulation of magmatic rocks. These might be fragments of oceanic crust or ophiolites marking previous subduction or obduction zones. Another explanation may be the intrusion of predominantly basic material during former crustal thinning or stretching. With the exception of the Saxothuringian and Donau Anomaly magnetic belts there is no indication of oceanic crust in the magnetic anomaly map.

The magnetic anomalies in the surroundings of the DEKORP 2-N profile — within a rectangle of 230 km N-S and 170 km E-W — are interpreted by a two-layer model where the shape of an interface between an upper nonmagnetic and a lower magnetized layer can be determined. The depth and the amplitudes of the vertical undulations of the interface may vary within certain intervals.