This dataset contains 80 U-Th ages of subaqueous grown speleothems (Hells Bells) from the north-eastern Yucatán Peninsula. These secondary carbonates were collected from three different sinkholes (cenotes) southwest of Cancún, Quintana Roo, Mexico (20.51–20.52°N, 87.01–87.07°W) at water depths between -29.4 m a.s.l and -37.3 m a.s.l. Samples were collected in situ and their elevation was measured with a dive computer (+-0.1m). For samples taken from the bottom of the cenotes, we cannot assign a corresponding water depth since we have no information about their original position on the cave ceiling. The measurements were carried out by a multi-collector inductively coupled plasma mass spectrometer (ThermoFisher Neptune Plus).

Errors are 2 sigma analytical errors (absolute uncertainties). All ages have been calculated with the half lives of Cheng et al., 2013. Corrected 230Th/U-ages assume an initial (230Th/232Th) activity ratio of 2 ± 1. 230Th/U-ages are given relative to the year 1950 (BP). Measurements were carried out at the Universities of Heidelberg (Germany) and Mainz (Germany).