Authors:	Homann, Julia Karbach, Niklas Carolin, Stacy A. James, Daniel H. Hodell, David Breitenbach, Sebastian F. M. Kwiecien, Ola Brenner, Mark Lope, Carlos Peraza Hoffmann, Thorsten
Title:	Past fire dynamics inferred from polycyclic aromatic hydrocarbons and monosaccharide anhydrides in a stalagmite from the archaeological site of Mayapan, Mexico
Online publication date:	8-Aug-2023
Year of first publication:	2023
Language:	english
Abstract:	Speleothems (cave stalagmites) contain inorganic and organic substances that can be used to infer past changes in local and regional paleoenvironmental conditions. Specific biomarkers can be employed to elucidate the history of past fires, caused by interactions among climate, regional hydrology, vegetation, humans, and fire activity. We conducted a simple solid–liquid extraction on pulverised carbonate samples to prepare them for analysis of 16 polycyclic aromatic hydrocarbons (PAHs) and three monosaccharide anhydrides (MAs). The preparation method requires only small samples (0.5–1.0 g); PAHs and MAs were measured by GC–MS and LC–HILIC–MS, respectively. Detection limits range from 0.05–2.1 ng for PAHs and 0.01–0.1 ng for MAs. We applied the method to 10 samples from a ∼ 400-year-old stalagmite from Cenote Ch'en Mul, at Mayapan (Mexico), the largest Postclassic Maya capital of the Yucatán Peninsula. We found a strong correlation (r = 0.75, p < 0.05) between the major MA (levoglucosan) and non-alkylated PAHs (Σ15). We investigated multiple diagnostic PAH and MA ratios and found that although not all were applicable as paleo-fire proxies, ratios that combine PAHs with MAs are promising tools for identifying different fire regimes and inferring the type of fuel burned. In the 1950s and 1960s, levoglucosan and Σ15 concentrations roughly doubled compared to other times in the last 400 years, suggesting greater fire activity at Mayapan during these two decades. The higher concentrations of fire markers may have been a consequence of land clearance at the site and exploration of the cave by Carnegie Institution archaeologists.
DDC:	540 Chemie 540 Chemistry and allied sciences 550 Geowissenschaften 550 Earth sciences 560 Paläontologie 560 Paleontology 600 Technik 600 Technology (Applied sciences) 620 Ingenieurwissenschaften und Maschinenbau 620 Engineering and allied operations 980 Geschichte Südamerikas 980 General history of South America
Institution:	Johannes Gutenberg-Universität Mainz
Department:	FB 09 Chemie, Pharmazie u. Geowissensch.
Place:	Mainz
ROR:	https://ror.org/023b0x485
DOI:	http://doi.org/10.25358/openscience-9363
Version:	Published version
Publication type:	Zeitschriftenaufsatz
Document type specification:	Scientific article
License:	CC BY
Information on rights of use:	https://creativecommons.org/licenses/by/4.0/
Journal:	Biogeosciences 20 15
Pages or article number:	3249 3260
Publisher:	Copernicus
Publisher place:	Katlenburg-Lindau [u.a.]
Issue date:	2023
ISSN:	1726-4189
Publisher DOI:	10.5194/bg-20-3249-2023
Appears in collections:	DFG-491381577-G