1 Speleothem-derived polycyclic aromatic hydrocarbons and monosaccharide anhydrides as tracers of past fire dynamics Julia Homann 1 , Niklas Karbach 1 , Stacy A. Carolin 2 , Dan James 3 , David Hodell 3 , Sebastian F. M. Breitenbach 4 , Ola Kwiecien 4 , Mark Brenner 5 , Carlos Lope 6 , Thorsten Hoffmann 1 1 Department of Chemistry, Johannes Gutenberg-Universität, Mainz, Germany 5 2 School of Archaeology, University of Oxford, Oxford, UK 3 Department of Earth Sciences, University of Cambridge, Cambridge, UK 4 Department of Geography and Environmental Sciences, Northumbria University, Newcastle upon Tyne, UK 5 Department of Geological Sciences, University of Florida, FL, USA 6 Instituto Nacional de Antropología e Historia, Centro INAH Yucatán, Mérida, México 10 Correspondence to: Thorsten Hoffmann (hoffmant@uni-mainz.de) Cave survey and stalagmite sample MAYA-22-7 Because only very rough scetch maps were available, our team surveyed part of Cenote Ch’en Mul in August 2022 (Fig. S1). The cenote is in direct vicinity to the Kukulcan temple and the observatory (structure Q-152) (Brown, 2006). The cenote has 15 been targeted in archaeological studies since the Carnegie Maya project 1952-1957 (Weeks and Masson, 2009). The cave extends from the collapse doline in north-easterly then easterly direction and results from an ancient underground stream. The overburden is only between 7 and 8 m thick and facilitates rapid infiltration. Today, the passages are characterised by large breakdown and washed-in silt- and clay-rich unconsolidated sediment. The sediment on the cave floor is rich in organic material that has been washed in during floods. Several trenches have been excavated (and filled in afterwards) in the 20 cenote and in the main cave passage, including a trench in 1953 and two trenches called ‘Bernard Trench’ (Brown, 2006). Hell Chamber in the north-eastern section of the cave hosts a large colony of bats and manifold centipedes and millipedes, crickets and other cave dwellers. Maya potsherds are widespread in all passages, indicating human activity in the past. While the main passage is largely devoid of secondary cave carbonates (speleothems), the side passages are very well decorated with stalagmites and stalactites. During our visit in 2022 the cave showed active dripping in only few places, especially in the SE, 25 where a small puddle was detected which might be linked to the water table. Stalagmite MAYA-22-7 (Fig. 1) was found a few meters above the puddle. It was active (i.e., dripwater was falling onto it) when it was collected. The stalagmite was packed in a large plastic zip-lock bag before being detached from the growth spot to avoid contamination of the youngest surface. 30