This dataset has been used in the framework of the REFINE project aiming to establish an age-depth model for Lake Bosumtwi (West Africa, Ghana) that bases on a combination of cyclostratigraphy and correlation analyses. For this the original NGR data obtained during the project for core GLAD6 BOS04 5B (also available at PANGAEA) have been smoothed using a 35 point mean and were correlated to Iberian Margin Sea Surface Temperatures (the tiepoints are also available at PANGAEA). This file contains the smoothed NGR data (and depths) and the correlative ages (linear interpolation between tiepoints). All original core data (GLAD6 BOS04 5B) have been retrieved in a ~4 cm resolution by the Continental Scientific Drilling Facility at the University of Minnesota, USA using a Geotek MSCL-S multisensor core logger equipped with a 3-inch diameter NaI(Tl) detector housed in a 6-inch diameter lead shield. Data are reported as total counts, integrating all emission counts over the gamma ray energy range between 0 and 3 MeV. For these measurements the archive core half has been used. Measurement uncertainties range between 5 and 10%. .