Gebhardt, Andrea Catalina; Ohlendorf, Christian; Kowalski, Sophie; Matthiessen, Jens; Wollenburg, Jutta Erika; Grotheer, Hendrik; Hoffman, Leon: A new chronological framework for Lake Melville sediments [dataset bundled publication]. PANGAEA, https://doi.pangaea.de/10.1594/PANGAEA.992015 (dataset in review)

Lake Melville, a fjord lake in Labrador, captures a rare and continuous record of postglacial environmental change at the interface of terrestrial and marine systems. During expedition MSM84 in 2019, five gravity cores were retrieved from the deep, eastern part of Lake Melville (MSM84_09-2, MSM84_18-1, MSM19-1, MSM84_26-1, and MSM84_28-1). Three of these cores were selected (MSM84_09-2, MSM84_18-1, and MSM84_26-1) to compile a composite profile (MSM84_LM-CP) that contains postglacial sediments in high resolution, and penetrates into deglacial and glacial sediments. A total of 45 samples were taken for AMS 14C dating, and measurements were carried out at the AWI MICADAS facility. 23 samples originated from MSM84_LM-CP; these were used to calculate an age-depth model. Age-depth modelling was done using Bayesian statistics implemented in the R-package 'rbacon' version 3.1.1 (Blaauw and Christen, 2011). The Marine20 (Heaton et al., 2020) radiocarbon age calibration curve was used. To account for the regional deviation of the world ocean, 14C age a local reservoir correction (ΔR-value) was applied for the conversion of 14C-ages into calendar ages. Because our oldest 14C-age yields a mean calibrated age of 10978 cal a BP i.e. younger than 11500 cal a BP we follow the recommendation of Heaton et al. (2023a,b) who suggest using the Holocene average ∆R-value for this region. For calculation of the regional ΔR-value we refer to Brouard et al. (2021) who did age recalibrations of data published for marine sediment archives in this region. Using data from McNeely et al. (2006) published in the Marine Reservoir Correction Database (http://calib.org/marine/) in which deposit feeders and unknown species were excluded, a ∆R-value of -2 ± 69 years (n=20) was calculated.