Bubble trail and folia in cenote Zapote, Mexico: petrographic evidence for abiotic precipitation driven by CO₂ degassing below the water table

Authors

Rafael López-Martínez, Carbonate and Karst Process Laboratory, Institute of Geology, National Autonomous University of MéxicoFollow
Fernando Gázquez, University of AlmeriaFollow
José M. Calaforra, University of AlmeriaFollow
Philippe Audra, Université Nice Côte d’AzurFollow
Jean Y. Bigot, 21 Rue des Hospices, 34090 Montpellier, FranceFollow
Teresa Pi Puig, National Laboratory of Geochemistry and Mineralogy, Institute of Geology, National Autonomous University of MéxicoFollow
Rocío J. Alcántara-Hernández, National Laboratory of Geochemistry and Mineralogy, Institute of Geology, National Autonomous University of MéxicoFollow
Ángel Navarro, The Gopro Family, Quintana Roo, MexicoFollow
Philippe Crochet, Photographe de la spéléologie et du monde minéra, FranceFollow
Liliana Corona Martínez, Centro de Geociencias (CGEO), National Autonomous University of MéxicoFollow
Raquel Daza Brunet, Carbonate and Karst Process Laboratory, Institute of Geology, National Autonomous University of MéxicoFollow

Highlights

• The origin of folia is still controversial
• In the Cenote Zapote occurs the biggest reported folia
• Folia are the result of subaqueous calcite precipitation around CO₂ bubbles

Abstract

Folia are speleothems that resemble bells, inverted cups, or bracket fungi, and whose origins are still controversial. Cenote Zapote (an underwater cave) in the Yucatán Peninsula (México), is home to some of the largest folia reported to date. These speleothems are currently growing in an active underwater system, meaning this site offers an excellent opportunity to constrain the different formation models proposed for folia, which have traditionally relied on inactive examples. In Cenote Zapote, folia are closely related to bubble trails and cupolas, suggesting an underwater CO₂-degassing process. In thin section, they display a succession of columnar-open and columnar-elongated endings in micrite-dendritic fabrics. Our petrographic and geochemical results demonstrate the abiotic origin of these folia and indicate carbonate precipitation from cold water by CO₂ degassing below the water table that started at least 5,210 yrs BP. We conclude that these folia formed as a result of subaqueous calcite precipitation around CO₂ bubbles trapped below overhanging walls of the cave. The sequential alternation of columnar and micritic fabrics can be explained by changes in the position of the halocline and H₂S-rich water mass while the exceptional size is the result of carbonate precipitation from waters saturated in CaCO₃ during thousans of years. Then we propose the classification of these speleothems as a subtype of folia. This subtype could be named Hells Bells, respecting its original description.

DOI

https://doi.org/10.5038/1827-806X.49.3.2344

Creative Commons License

This work is licensed under a Creative Commons Attribution-Noncommercial 4.0 License

Recommended Citation

López-Martínez, Rafael; Fernando Gázquez; José M. Calaforra; Philippe Audra; Jean Y. Bigot; Teresa Pi Puig; Rocío J. Alcántara-Hernández; Ángel Navarro; Philippe Crochet; Liliana Corona Martínez; and Raquel Daza Brunet. 2020. Bubble trail and folia in cenote Zapote, Mexico: petrographic evidence for abiotic precipitation driven by CO₂ degassing below the water table. International Journal of Speleology, 49: 173-186.
Available at: https://digitalcommons.usf.edu/ijs/vol49/iss3/1