The core RAPiD-21-03K was scanned using an ITRAX X-Ray Fluorescence core scanner at 0.002 m (1.6 year) resolution for flux quantification. Br and Si intensities were calibrated into weight fraction Br and SiO2 using the protocol from Weltje, G. J. et al. (2015). In this dataset, 'depth' is the midpoint distance each sediment sample was taken from the top of the core in m, 'age' is the calibrated age in both years before present and in common era calendar years, 'Br', 'SiO2' is the mass fraction of bromine or silica at each depth following calibration of the XRF-derived intensity, 'isoutlier' identifies Br or SiO2 mass fraction values more than three scaled median absolute deviations from the median. 'Br', 'SiO2' is the mass fraction of bromine or silica at each depth following calibration of the XRF-derived intensity, 'isoutlier' identifies Br or SiO2 mass fraction values more than three scaled median absolute deviations from the median.