Reconstruction of the Maya-driven early anthropocene in Central Guatemala from multielemental proxies in a lake sediment record

The Maya population is recognized as one of the first whose activities have significantly impacted the natural environment much earlier than industrial revolution[1].Still, the actual scale of such impacts and their possible role in driving the collapse of Maya civilization are currently a matter of debate[2]. In this study, a sedimentary record from Lake Petén Itzá, central Guatemala, was analysed for trace, platinum group and rare earth elements to reconstruct the evolution of their concentration, enrichment factor and flux over the last 6000 years. Complementary measurements of total organic and inorganic carbon provided contextual data on the variation of sediment’s composition over time. The results showed substantial alterations of the natural geochemical equilibrium due to thedeforestation, agriculturalpractice and general land use during the over 2000 years of Maya occupation, strongly associated to demographic trends and the sequence of cultural periods. Increased soil erosion, exacerbated by high rainfall, raised the flux of traces-depleted clastic materials to the Lake from Maya settlement around 1000 B.C., up to a maximum between 400 B.C. and 200 A.D. During the subsequent classical period, at the top of demographic expansion, drier climate and the introduction of more sustainable agricultural practices mitigate the erosion processes, but a substantial recovery of the ecosystem took place only after the sudden collapse of Maya civilization around 1000 A.D., and the consequent restoration of tropical forest. While possible signs of volcanic events were observed, which could have affected some human activities (e.g. production of ceramics), no significant evidences of pollution liked to metallurgy was revealed during Maya occupation. The results are discussed in the context of literature data including paleofire and paleovegetation reconstructions, and archaeological proofs, to provide a comprehensive view of the state-of-the art in the knowledge of how the Maya civilization transformed the surrounding environment.