Description: Varved lake sediments provide climatic records with seasonal to annual resolution and low associated age uncertainty. Robust and detailed comparison of well-dated and annually laminated sediment records is crucial for reconstructing abrupt and regionally time-transgressive changes as well as validation of spatial and temporal trajectories of past climatic changes. The VARved sediments DAtabase (VARDA) presented here is the first data compilation for varve chronologies and associated palaeoclimatic proxy records. The current version 1.0 allows detailed comparison of published varve records from 95 lakes. VARDA is freely accessible and was created to assess outputs from climate models with high-resolution terrestrial palaeoclimatic proxies. VARDA additionally provides a technical environment that enables us to explore the database of varved lake sediments using a connected data model and can generate a state-of-the-art graphic representation of a multisite comparison. This allows the reassessment of existing chronologies and tephra events to synchronize and compare even distant varved lake records. Furthermore, the present version of VARDA permits the exploration of varve thickness data. In this paper, we report in detail on the data-mining and compilation strategies for the identification of varved lakes and assimilation of high-resolution chronologies, as well as the technical infrastructure of the database. Additional palaeoclimatic proxy data will be provided in forthcoming updates. The VARDA graph database and user interface can be accessed online at https://varve.gfz-potsdam.de (last access: 15 September 2020), all datasets of version 1.0 are available at https://doi.org/10.5880/GFZ.4.3.2019.003 (Ramisch et al., 2019).

Description: This dataset resulted from a parallel monitoring at two lakes, Lake Tiefer See (near Klocksin, TSK; 53° 35.5’ N, 12° 31.8’ E; 62 masl; N Germany) and Lake Czechowskie (Jezioro Czechowskie, JC; 53° 52.4’ N, 18° 14.3’ E; 108 masl; N Poland), and includes four different type of data for both locations: (i) sediment cores microfacies data, (ii) sediment fluxes and composition, (iii) selected water column data, and (iv) selected meteorological information obtained on site. This dual lake monitoring set-up was established in 2012 with the aim to investigate seasonal sedimentation and varve forming processes in detail. The datasets are provided in individual *.csv files, per type of data and per lake. The thin section data from surface sediment cores comprises the thicknesses of the most recent calcite varves’ sub-layers: spring diatom sub-layer, summer calcite sub-layer, and autumn/winter re-suspension sub-layer. The sediment flux data was obtained from sediment traps located in different water depths (epi- and hypolimnion), and the sediment composition is given by the fluxes of total organic carbon (TOC), calcium carbonate (as calculated from total inorganic carbon; TIC), and diatoms & inorganic matter. The water column data comprises water temperature from stationary loggers, and dissolved oxygen measured in ~ 1 meter depth-resolution. The meteorological data includes daily averages of air temperature and mean wind-speed, and summed daily rainfall. Further details about the sampling and analytical methods, data acquisition, and processing are given in Roeser et al. (2021; http://doi.org/10.1111/bor.12506).

Description: This report describes the KTB Borehole Measurements Data of the German Continental Deep Drilling Program (Kontinentales Tiefbohrprogramm der Bundesrepublik Deutschland), operated by the GFZ German Research Centre for Geosciences. Extensive borehole measurements were performed during the active drilling phase of the KTB pilot and main hole (1989-1994). This report provides the full description of the logging data. Please read it thoroughly to avoid inappropriate or wrong use of the data. The terms borehole measurements, downhole logging, and logging are used synonymously here. The KTB logging data files contain the final processed versions of the geoscientific borehole logging data from logs in the two KTB boreholes: Boreholes Geographic Coordinates (WGS84) KTB-Oberpfalz VB (KTB Vorbohrung/Pilot Hole or KTB-VB) 49.8153 N, 12.118 E KTB-Oberpfalz HB (KTB Hauptbohrung/Main Hole or KTB-HB) 49.8152 N, 12.1205 E