Evidence of large water-level variations found in deltaic sediments of a tropical deep lake in the karst mountains of the Lacandon forest, Mexico

• DOI: 10.1007/s10933-022-00264-7
• Publication Date: 2022-09-13T22:02:28Z
• Authors: Rodrigo Martínez-...; Matthias Bücker; Johannes Hoppenbrock; Adrian Flores-Orozco; Carlos Pita de la...; Karoline Fröhlich; Johannes Buckel; Theresia Lauke; Bárbara Moguel; Mauricio Bonilla; Karla Rubio-Sandoval; Paula Echeverría-...; Santiago Landois; Miguel García; Margarita Caballero; Sergio Rodríguez; Wendy Morales; Oscar Escolero; Alexander Correa-...; Marta Wojewódka-P...; Anja Schwarz; Kim Krahn; Antje Schwalb; Liseth Pérez
• Keywords: River delta

Abstract Lake Tzibaná is one of the largest (1.27 km 2 ) and deepest (Z max = 52 m) karstic lakes in UNESCO’s Biosphere Reserve “Nahá-Metzabok” Lacandon Forest, southeastern Mexico. It archives sediments from multiple sources inflowing Nahá River forms deltaic deposits. In 2019, water level declined by ~ 15 m, persisting for 4 months exposing Delta. A geophysical profile on exposed delta revealed an accumulation 20 m such Three sediment outcrops inactive channel Delta, which ranged height 0.6 to 1.43 were sampled a multi-proxy analysis biological remains geochemical variables was conducted. Four facies observed: (1) massive-coarse sand, (2) fine (3) dark leaf litter (4) massive silty clay, each characterized specific microcrustacean, testate amoebae diatom taxa. Six horizons radiocarbon dated complex depositional history including inverted ages making establishment age model difficult. Nevertheless, past lake-level changes formation four match three characteristic water-level stages, can also be observed recent satellite images: Massive-coarse sand deposits, with compositional sedimentological characteristics shoreline environment fluvial lateral banks, formed during large-magnitude reductions lake level, similar Interbedded layers litter, currently found low-energy environments, shorter less pronounced decrease intervals, Massive distinctive microorganisms lacustrine deposited high when covered water. Our findings illustrate how hydrological alter sedimentary dynamics areas lakes. Despite complexity their processes, records serve as complementary source paleolimnological information distal zones due sensitivity variations especially extreme prolonged desiccation events. Future research should attempt combine evidences sequences deeper reconstruct entire Holocene. Understanding not only relevant local indigenous communities but crucial conservation this ecosystem international importance.