Response of a low elevation carbonate lake in the Yucatan Peninsula (Mexico) to climatic and human forcings

The importance of climate change, specifically drought, across the Maya region in the northern Neotropics, remains a topic of lively debate. Part of this discussion hinges on the coherency of response to climatic variability across different archives and proxies. In this paper we present a 6600-year palaeolimnological record from Yaal Chac, a carbonate lake (known locally as a cenote) in the northern lowlands of the Yucatan Peninsula, < 2 km from the location of the previously published Aguada X'Caamal record. The Yaal Chac sequence has been analysed for loss-on-ignition (L01), stable isotopes (delta O-18, delta C-13) and elemental analysis using mu XRF, complemented by some mineralogical, charcoal and pigment data. Mid Holocene sediments, predating evidence of human impact, are carbonate dominated and finely laminated. delta O-18 values are positive (>2 parts per thousand), but show no covariation with delta C-13. A major transition occurs at ca. 4360 cal yr BP, with a change to generally more organic sediments and increased variability in all proxies. Although direct evidence for anthropogenic activity in the Yaal Chac catchment is limited, it seems feasible that human impact was affecting the system. Comparison with other records from the Northern Maya lowlands and the wider region shows little coherence in the mid Holocene, when Yaal Chac seems to have been quite stable, but possibly responsive to increased climatic seasonality, driving the production of seasonal laminae. In the late Holocene, when the climate was generally more variable, there is more coherence between Yaal Chac and other regional records, including the so called Pan Caribbean Dry Period (3500-2500 cal yr BP) and the droughts of the late Pre-Classic period (1800-1600 cal yr BP). The Yaal Chac record shows no evidence of drought at the time of either the Maya 'hiatus' or the Maya 'collapse' of the Terminal Classic, but does record drying from the 14th to 19th centuries CE, in keeping with other proxy and historical records. This new record from Yaal Chac highlights the spatial variability of responses to climate forcings and the importance of recognising individual system sensitivity. (C) 2022 The Authors. Published by Elsevier Ltd.

Automated summary

This study examines the importance of climate change, specifically drought, in the Maya region by analyzing a 6600-year paleolimnological record from Yaal Chac, a carbonate lake in the Yucatan Peninsula. The findings reveal that Yaal Chac responded differently to climate variability in the mid Holocene and late Holocene. In the mid Holocene, the lake was stable but possibly influenced by increased climatic seasonality. In the late Holocene, there was more coherence between Yaal Chac and other regional records, indicating a more variable climate. The record also shows evidence of drying in the 14th to 19th centuries CE, consistent with other proxy and historical records.