X-ray fluorescence core scanning (XRF-CS) data of sediment core LAc22-1 retrieved from Lake Alchichica in April 2022. Scans were performed with a 2 mm step size and 20 seconds dwell time. The elemental data were transformed using the centered log-ratio (clr) method and thereafter min-max normalized. The analysis yielded the ratio of Compton (incoherent) to Rayleigh (coherent) scattering (Inc/coh) that can be used as an indicator of sediment organic matter content. The measurements extend back to the late 1800s. Ages were estimated using Pb-210 dating and Bayesian age-depth modeling.