Water-level change recorded in Lake Pac Chen Quintana Roo, Mexico infers connection with the aquifer and response to Holocene sea-level rise and Classic Maya droughts

Paleoindian ochre mines in the submerged caves of the Yucatán Peninsula, Quintana Roo, Mexico

“…Before the inundation of the cave by postglacial sea-level rise, the ochre miners used one of three surface entry points, Entrada Pu'bix, Entrada Sagitario, or Entrada Kilix Pach-Och (Fig. 1C) (1,7,21,22). All mining activity is located well into the dark zone of the cave.…”

“…(table S2), consistent with evidence from Hoyo Negro that sea level surmounted 9 to 11 m below modern sea level between 8.0 and 7.0 ka. Groundwater levels in the region track sea level closely (7,21,22), so water levels in the Sagitario system and Hoyo Negro, 8 and 6 km inland, respectively, should be equivalent. Therefore, our evidence indicates that mining activities in this system were abandoned well before 8.0 ka.…”

“…(table S2), consistent with evidence from Hoyo Negro that sea level surmounted 9 to 11 m below modern sea level between 8.0 and 7.0 ka. Groundwater levels in the region track sea level closely (7,21,22), so water levels in the Sagitario system and Hoyo Negro, 8 and 6 km inland, respectively, †These are age estimates based on ages of other charcoal fragments in the same collection unit, as presented for samples 150515-6d and 150515-6e. This is true also for the two samples below, which come from collection units 171128-16 and 17128-25, for which estimates are based on dates for 171128-16a and 171128-25a, respectively.…”

Inland Tidal Oscillations Within the Yucatan Peninsula

“…The high porosity of the limestone (14%–23%;​ Beddows et al., 2007) results in few surface water bodies (e.g., lakes), as rainfall quickly infiltrates through the limestone and into the unconfined aquifer which flows toward the coast through networks of caves and fracture zones (Beddows et al., 2007; Emblanch et al., 2003; Stoessell, 1995). The few surface water bodies that do exist are thought to contain draping layers of sediment which act as an aquitard (Curtis et al., 1996; Brenner et al., 2002; Hodell, Brenner, & Curtis, 2005; Krywy‐Janzen et al., 2019). This effectively hydrologically isolates these water bodies from the larger aquifer‐ocean water body, and implying that changes in water level correlate with evaporation/precipitation.…”

“…More recently Krywy‐Janzen et al. (2019) used sediment cores and water level reconstruction within Pac Chen (Pac Chen; site (D) in this publication; an enclosed freshwater lake approximately 42 km inland) to show that its water level evolved in response to sea level changes throughout the Holocene. Additionally, the authors also directly measured centimeter‐scale oscillations in water level with a diurnal and semi‐diurnal frequencies during a 6 month period.…”