A 6,000-year record of environmental change from the eastern Pacific margin of central Mexico

Davies, Sarah J.; Metcalfe, Sarah E.; Aston, Benjamin J.; Byrne, A. Roger; Champagne, Marie R.; Jones, Matthew D.; Leng, Melanie J.; Noren, Anders

Abstract

The transition from the mid- to late-Holocene in MesoAmerica saw increasing complexity in spatial patterns of change. Records from the western part of the region are sparse, with lacustrine sequences affected by long term anthropogenic disturbance or lacking chronological resolution. Here, we present a continuous palaeoecological and geochemical record from Laguna de Juanacatlán, a remote lake in the mountains of the western TMVB. Diatom assemblages, XRF scanning data and bulk organic geochemistry from a well-dated, 7.25-m laminated sequence were combined with summary pollen data from a 9-m partially laminated core to provide a continuous record of catchment and lake ecosystem changes over the last c. 6,000 years. Relatively humid conditions prevailed prior to c. 5.1 cal ka, which supported dense oak-pine forest cover around a deep, stratified lake. A trend towards drier conditions began c. 5.1 cal ka, intensifying after 4.0 cal ka, consistent with weakening of the North American Monsoon. Between 3.0 and 1.2 cal ka, lower lake levels and variable catchment run-off are consistent with increasing ENSO influence observed in the Late Holocene in the neotropics. From 1.2 to 0.9 cal ka, a marked change to catchment stability and more intense stratification reflected drier conditions and / or reduced rainfall variability and possibly warmer temperatures. After 0.9 cal ka, conditions were wetter, with an increase in catchment disturbance associated with the combined effects of climate and human activity. In recent decades, the lake ecosystem has changed markedly, possibly in response to recent climate change as well as local catchment dynamics.

Citation

Davies, S. J., Metcalfe, S. E., Aston, B. J., Byrne, A. R., Champagne, M. R., Jones, M. D., …Noren, A. (2018). A 6,000-year record of environmental change from the eastern Pacific margin of central Mexico. Quaternary Science Reviews, 202, 211-224. https://doi.org/10.1016/j.quascirev.2018.11.008

• Journal Article Type: Article
• Acceptance Date: Nov 8, 2018
• Online Publication Date: Nov 22, 2018
• Publication Date: Dec 15, 2018
• Deposit Date: Nov 15, 2018
• Publicly Available Date: Nov 23, 2019
• Journal: Quaternary Science Reviews
• Print ISSN: 0277-3791
• Publisher: Elsevier
• Peer Reviewed: Peer Reviewed
• Volume: 202
• Pages: 211-224
• DOI: https://doi.org/10.1016/j.quascirev.2018.11.008
• Public URL: https://nottingham-repository.worktribe.com/output/1269232
• Publisher URL: https://www.sciencedirect.com/science/article/pii/S0277379118302464
• Additional Information: This article is maintained by: Elsevier; Article Title: A 6,000 year record of environmental change from the eastern Pacific margin of central Mexico; Journal Title: Quaternary Science Reviews; CrossRef DOI link to publisher maintained version: https://doi.org/10.1016/j.quascirev.2018.11.008; Content Type: article; Copyright: © 2018 Elsevier Ltd. All rights reserved.
• Contract Date: Nov 15, 2018