Age-depth models for Pb-210 datasets. The St Croix Watershed Research Station, of the Science Museum of Minnesota, kindly made available 210Pb datasets that have been measured in their lab over the past decades. The datasets come mostly from North American lakes. These datasets were used to produce both chronologies using the 'classical' CRS (Constant Rate of Supply) approach and also using a recently developed Bayesian alternative called 'Plum'. Both approaches were used in order to compare the two approaches. The 210Pb data will also be deposited in the neotomadb.org database. The dataset consists of 3 files; 1. Rcode_Pb210.R R code to process the data files, produce age-depth models and compare them. 2. StCroix_agemodel_output.zip Output of age-model runs of the St Croix datasets 3. StCroix_xlxs_files.zip Excel files of the St Croix Pb-210 datasets

A Bayesian age-depth model was constructed of the radiocarbon dates of the MexiDrill composite core. The age-depth model was produced using rbacon (Blaauw and Christen 2011, Bayesian Analysis 6(3): 457-474, doi: 10.1214/11-BA618), and was run in R as rbacon (CRAN version 3.2.0) using all default settings except for: thick=0.2, depth.units="m", ka=TRUE, acc.mean=2000. The output consists of a pdf of the age-depth model and its settings, a file containing the 95% age ranges, medians and means for every 0.1m of the core depths, a settings file and the .csv file that was used to produce the age-depth model. During the age-modelling, rbacon used the IntCal20 northern hemisphere terrestrial calibration curve (Reimer et al. 2020, Radiocarbon 62, 725-757, doi:10.1017/RDC.2020.41).

The MexiDrill core was dated using a range of methods, including radiocarbon. Samples of sediment were pretreated (acid-only) at the 14CHRONO Centre according to established protocol, and measured using Accelerator Mass Spectrometry (AMS). The plain-text file lists the uncalibrated AMS radiocarbon dates, with the following columns: UBA ID, date submitted, MexiDrill sample ID, radiocarbon age, and lab error.

Peat properties data and age depth models for 102 peat cores extracted and analysed for the Increased Carbon Accumulation in Arctic Peatlands (ICAAP) project (Grant NE/S001166/1). Peat cores were extracted from 12 peatland sites from four regions of the Arctic: Svalbard, Norwegian and Finnish Lapland, Nunavut, Canada and Quebec, Canada Data originates from the analysis of Arctic peat cores for changes in rates of lateral expansion and vertical peat accumulation during recent centuries. Specifically, peat cores were analysed for moisture content (%), dry bulk density (g cm-3), C/N content (%), 210Pb activity levels (bq/kg), and 14C radiocarbon age (yr BP). Svalbard (78.09065°N 14.98407°E; 78.98595°N, 11.98246°E; 78.95872°N, 11.68331°E) Norwegian and Finnish Lapland (70.11876°N, 28.48351°E; 69.80659°N, 27.19732°E, 69.38787°N, 24.24123°E), Nunavut, Canada (72.655515°N, 78.061646°W; 72.694207°N, 77.864603°W; 73.13028°N, 80.022987°W) Quebec, Canada (62.165681°N, 75.915017°W; 62.123168°N, 75.769467°W; 62.157355°N, 75.607301°W)