A 1,000-YEAR PALYNOLOGICAL RECORD OF LAKE IZABAL, EASTERN GUATEMALA

Lake Izabal is the largest lake in Guatemala with a surface area of 589.6 km² and a maximum depth of 15m. It is located in a seismically active basin along the Polochic Motagua Fault System, the inland extension of the North America and Caribbean plate boundary. Pilot surveys in the lake indicate that sediment deposition in the basin began in the Early Miocene with a thickness that is greater than 4 km; the top 1500 m appear to have been deposited continuously in a lacustrine environment. The acquisition of a ~5 m-long Punta Chapin core in the southern part of the lake provides an opportunity to study the palynological record of the last 1,000 years, based on extrapolation from five radiocarbon dates. The core is characterized by laminated organic-rich mud with thin beds of silt and fine sand. Initial recovery of palynomorphs in the core is excellent and characteristic of good preservation. The assemblage is pollen dominated comprising taxa from the surrounding and catchment areas, such as montane forest pollen (e.g. Myricaceae and Podocarpus) lowland taxa (e.g. Moraceae-Urticaceae, Spondias), Pinus, in addition to disturbance taxa (e.g. Ambrosia, Poaceae). Spores, nonmarine algae and fungi also occur in the assemblage. The pollen record will be used to provide insights into the climatic and environmental conditions that prevailed in eastern Guatemala during and after the collapse of the Mayan civilization.