9709314 Hodell The Department of Peten in northern Guatemala represents the central area where ancient Maya civilization arose more than 3000 years ago, flourished during the so-called Classic Period, and mysteriously collapsed around 800 - 900 AD. The cause of the Collapse has been debated by archaeologists for over a century. Climate change has been suggested as a contributing factor, but this hypothesis has not been tested rigorously. Our previous work, funded by NOAA-Paleoclimatology, sought to understand the role that climate change may have played in the collapse of Maya civilization. We discovered compelling paleoclimatic evidence from two lakes in central and northern Yucatan for a protracted drought between ~800 and 1000 AD that coincided with the Classic Maya Collapse (Hodell et al., 1995; Curtis et al., 1996). Correlation of arid events in paleoclimate records between Yucatan lakes and the Peruvian Quelccaya ice core suggests that aridity was widespread in Central and South America over the last 1500 years, and may have been related to large-scale departures in atmospheric and oceanic fields. Here we propose to test if the droughts documented in Yucatan affected the southern Maya lowlands of Peten, Guatemala, where Maya population densities were highest and the Collapse was most profound. We propose to collect geochemical, palynological, and sedimentologic data from sediment cores taken in the Peten Lake District to reconstruct climatic and ecologic changes in sufficient detail to reveal decadal to centennial fluctuations over the past 5,000 years. Specifically, we will measure oxygen isotopic ratios in microfossil shells (ostracods and gastropods) from cores taken in close-basin lakes and reconstruct changes in the ratio of evaporation to precipitation (E/P) over the catchment. We will also document stratigraphic changes in pollen spectra from the same cores to reconstruct regional vegetation changes that may have been influenced by climatic factors and/or human impact. The proposed study will elucidate the spatial and temporal pattern of changes in E/P and vegetation in the Maya lowlands during the late Holocene. Paleoenvironmental records from Peten will contribute to our understanding of: 1.) the full range of natural hydrometeorologic variability during the Holocene in the lowland Neotropics; 2.) teleconnective linkages with climatic records (marine, lacustrine, and ice core records) from other regions; and 3.) the response of Classic Maya social and economic systems to climate and ecologic change.
