HR: 1340h
AN: PP43A-0658    [Abstracts]
TI: Reconstruction of Holocene Climate Variability within the Central Mediterranean Using Lake Sediments from the Akrotiri Peninsula, Crete
AU: * Magill, C R
EM: crm53@pitt.edu
AF: University of Pittsburgh, Department of Geology and Planetary Science, Pittsburgh, PA 15260 United States
AU: Rosenmeier, M F
EM: mrosenme@pitt.edu
AF: University of Pittsburgh, Department of Geology and Planetary Science, Pittsburgh, PA 15260 United States
AU: Cavallari, B J
EM: bjc22@pitt.edu
AF: University of Pittsburgh, Department of Geology and Planetary Science, Pittsburgh, PA 15260 United States
AU: Curtis, J H
EM: curtisj@ufl.edu
AF: University of Florida, Department of Geological Sciences, Gainesville, FL 32611 United States
AU: Weiss, H
EM: harvey.weiss@yale.edu
AF: Yale University, Department of Near Eastern Languages and Civilizations, New Haven, CT 06520 United States
AB: Middle and late Holocene geochemical records from the Limnes depression, a small sinkhole located within the Akrotiri Peninsula, Crete, document centennial and millennial-scale climate variability within the central Mediterranean region. The oldest sediments of the basin consist largely of fibrous plant macrofossils and organic matter and likely indicate lake filling and expansion of wetland vegetation beginning ~5700 radiocarbon years before present (¹⁴C-yrs B.P.) (4550 B.C.). The basal peat layers grade into predominantly open water and less shallow lacustrine deposits by 4500 ¹⁴C-yrs B.P (3200 B.C.). Continuous open water sedimentation within the Limnes core is interrupted by a number of distinct lag deposits and peaty deposits centered at 3700, 1600, and 350 ¹⁴C-yrs B.P (2100 B.C., 500 A.D., and 1500 A.D.) indicating periods of significantly lowered lake level or perhaps lake desiccation. These ages coincide roughly with oxygen isotope (δ¹⁸O) minima measured in biogenic carbonates (ostracod shells) and support the inference for low lake stage. Trace element (Ca, Mg, and Sr) concentrations in ostracod shells from the Limnes core parallel the oxygen isotope record, suggesting that the data reflect basin hydrology rather than changes in the isotopic composition of rainfall. Furthermore, covariance in both δ¹⁸O and Mg concentrations eliminate temperature as a control on the oxygen isotope record. Sediments from the basin also contain aragonite remains of the green alga Chara and isotope analysis of the calcite may record additional paleoenvironmental information. The paleoclimate history inferred from the Limnes record correlates temporally (albeit tenuously) to previous paleoenvironmental data that document abrupt onset of arid conditions in the eastern Mediterranean and western Asia ca. 2200 B.C. Moreover, stratigraphic and geochemical evidence of low lake level (drying) within the Limnes basin at 2100 B.C. may correspond to the termination of the Early Minoan II (Early Bronze Age) culture.
UR: http://www.pitt.edu/~mrosenme/greece.htm
DE: 1041 Stable isotope geochemistry (0454, 4870)
DE: 1051 Sedimentary geochemistry
DE: 1065 Major and trace element geochemistry
DE: 3305 Climate change and variability (1616, 1635, 3309, 4215, 4513)
DE: 3344 Paleoclimatology (0473, 4900)
SC: Paleoceanography and Paleoclimatology [PP]
MN: Fall Meeting 2005