HR: 15:20h
AN: GC53A-11    [Abstracts]
TI: A 7000 C-14 Year Record of Environmental Change From North Central Cuba: Implications for Regional Sea Level and Climate Change
AU: * Peros, M C
EM: matthew.peros@utoronto.ca
AF: University of Toronto Department of Geography, 100 St. George Street, Toronto, ON M5S 3G3 Canada
AB: Paleoenvironmental records from the Caribbean are rare. To fill in this gap, a study of Laguna de la Leche, a 67 square kilometer coastal lake located in north central Cuba, was undertaken. Sediment cores were extracted from this lake and its vicinity in order to study to the Holocene sea level and climate history of the area. The cores were studied using pollen, benthic foraminifera, and stable isotopes of oxygen and carbon. A chronology was established by radiocarbon dating. The results show that from approximately 7000 C-14 years to 5000 C-14 years B.P., Laguna de la Leche was a marsh dominated by cattail (Typha domingensis). From 5000 C-14 years to the present, water level rose, turning the marsh in to a shallow, saline lake. Beginning around 1700 C-14 years B.P., mangroves expanded across the area, and are presently prograding into Laguna de la Leche. It is anticipated that over the next several hundred years, Laguna de la Leche may be completely infilled by mangroves. The cause of the rise in lake level appears to have been driven mostly by relative sea level rise. Pollen records from Florida and southern Alabama show an abrupt transition from oak-grassland to pine dominated systems at roughly 5000 C-14 years B.P. This shift from dryer to wetter conditions has been interpreted as representing an increase in the water table due to regional sea level rise (Watts and Hansen, 1994), and is coincident with the marsh-lake transition at Laguna de la Leche. The possibility that an increase in precipitation occurred at 5000 C-14 years B.P. is still being studied, but an oxygen isotope record from Haiti (Hodell et al., 1991) provides no evidence for such a climatic shift.
DE: 3344 Paleoclimatology
DE: 4267 Paleoceanography
DE: 4556 Sea level variations
DE: 3040 Plate tectonics (8150, 8155, 8157, 8158)
DE: 1040 Isotopic composition/chemistry
SC: Global Climate Change [GC]
MN: 2004 AGU Fall Meeting