Profiles of chemical composition in the water column of blue holes and cenotes have been used previously to estimate water–rock reactions and hydraulic parameters and variations in head resulting from tidal fluctuations have been used to estimate hydraulic parameters. No geochemical observations have been conducted at tidal time scales or made sequentially through numerous tidal cycles. In this paper, we present measurements of water levels and limited chemical data (specific conductivity, dissolved oxygen concentrations, and pH) that were collected at high spatial and temporal resolution over several tidal cycles from blue holes on San Salvador Island and Rum Cay, Bahamas using logging environmental sensors. The data provide estimates of aquifer properties, provide constraints on how tidal pumping affects exchange between the ocean, blue holes, and the aquifer, and reflect diagenetic alteration of the aquifer rocks. Most modern carbonate platforms lack allogenic catchments, allowing rainfall to recharge the aquifer uniformly without sufficiently altering head gradients to drive exchange between conduits and aquifers. Some modern carbonate platforms experience tidal variations which could lead to head gradients that drive exchange. To determine the impact of tides on exchange, we measured water elevations at high temporal resolution in the ocean, blue holes and wells. |