Paleohydrological Proxies for Anchialine Cave Systems

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Every year, thousands of Canadians visit the Yucatan Peninsula's Maya Riviera staying at large resorts often swimming in nearby cenotes during their stay. Most are not aware that these cenotes are entry points for a vast subterranean cave system that extends beneath their resorts and is important groundwater source for the local population. This groundwater is coming under increased threat from human development through groundwater extraction and waste contamination. Groundwater is also very sensitive to larger scale factors such as global sea-level rise which is predicted to be 1m by the end of the 21st century but also other effects of climate change (eg. precipitation, frequency of hurricanes). ***Groundwater was important for past populations as well. In the early Holocene, when glaciers in northern latitudes were retreating Paleoamericans ˜12-13,000 yrs ago had already arrived in the Yucatan and many of their skeletons have been found in the caves. These early inhabitants of the Yucatan likely died in search of groundwater, getting lost in the cave or falling into pits (eg. Naia, Globe and Mail, May 16th, 2014). Groundwater was also important for the Classic Maya and their large population centers (eg. Chichen Itza, Coba) during the 3rd-10th c. AD but we have little information on past groundwater condition (i.e. its salinity or potability) or how much, and when it may have been used by the Maya. ***Our research on sediments accumulations from these caves will reconstruct the potability (saltiness) of the groundwater over the past 10,000 years and understand how the aquifer responded to climate and sea-level changes. Our research has shown that cave sediments and their physical, chemical and biological composition contain evidence of groundwater characteristics through time but there is little research devoted to the subject. The outcomes from this research will contribute to important archaeological questions on how and when early Paleoamericans migrated to the Yucatan, but also contribute to the debate on the decline of the Classic Maya with droughts in the 8th and 9th c. AD. The rise and fall of Mayan societies in the Yucatan have been linked with climatically wet and dry periods, although there is spatial complexity in this relationship that remains unexplained. The proposed research will contribute to this debate, as the availability of potable groundwater hasn't been considered and may provide additional information on the spatial patterning of Classic Mayan population centers. The outcomes of this interdisciplinary research (earth science and archaeology) will allow us to better understand how the aquifer was affected by climate and sea-level changes and better predict future response.**