USING CAVE AND CARBONATE DEPOSITS FOR PALEOENVIRONMENTAL RESEARCH IN THE KARST LANDSCAPE OF THE VACA PLATEAU, BELIZE

Recent studies have sought to better understand the socio-environmental dynamics of the Maya civilization in Belize, and since 2004 research in the north Vaca Plateau has focused on using geological proxies for reconstructing local and regional paleoenvironmental conditions. Since 2007, studies using cave deposits from the Vaca Plateau have proven to be effective in delineating periods of climatic and land use change sequences that help explain the waning of the Maya population in the area. To further refine the paleoenvironmental information that is already known about the study area, several lines of investigation were initiated in 2010 involving geoarchaeological field reconnaissance, and sampling of cave sediments and carbonate deposits to compliment the developing archaeological record. The primary research area focuses on the Minanha and Lower Dover archaeological sites. During two field seasons (2010, 2012), eight sediment core samples from caves in the study area, and two tufa samples from surface stream deposits near the Lower Dover and Minanha sites, were collected. Eleven radiocarbon dates from the first field season’s sediment core samples proved to be unreliable in their ages and chronology to use for paleoenvironmental reconstruction, but helped to inform sampling site selection for this year’s fieldwork. Currently, processing of the four new sediment cores is underway for radiocarbon dating, with a focus on establishing a chronology of up to 2k years. Future work on these core samples involves extracting humic acids (HAs) and fulvic acids (FAs) from the sediments for δ¹³C analysis according to a modified method to provide a proxy record of vegetation change driven by climatic variability and land use change from past human-environmental interactions. Additionally, analysis of the tufa samples for radiocarbon dating and palynological analysis will complement the sediment study and provide a comparison for the isotopic record with regard to vegetation dynamics. A driving hypothesis is that the location of these Maya population centers were the first to be susceptible to increasing drought and environmental degredation because of the nature of the highly-drained, thinly mantled karst topography, leading to issues with access to water for agricultural purposes.