Controlling factors on a paleo-lake oxygen isotope record (Yammoûneh, Lebanon) since the Last Glacial Maximum

摘要: Abstract Late Quaternary paleoclimatic changes in the Levant are difficult to extract from carbonate oxygen isotope records partly because factors controlling terrestrial δ18O signals not fully understood this region characterized by sharp climatic gradients. Here, we address purpose presenting first 14C-dated record northern Levant. The is based on isotopes ostracod shells lacustrine-palustrine deposits accumulated a small karstic, hydrologically open basin (Yammouneh), located eastern flank of Mount Lebanon. We have constructed composite isotopic obtained three different taxa. This yields an ostracods (δost) related most widespread species (Ilyocypris inermis), and converted values coeval with calcite precipitated equilibrium (δC) lake water (δL). As other Mediterranean region, Yammouneh profile shows maximum minimum δC during LGM early Holocene, respectively, slight late Holocene increase. In order discuss potential causes observed fluctuations (e.g., composition moisture source, temperature, precipitation minus evaporation (P-E) balance, or atmospheric circulation), tentatively reconstruct correcting for temperature using regional paleotemperature estimates. Inferred δL were then corrected Eastern sea surface (the source) derived planktonic foraminifera alkenone-based temperature. Our study suggests that primarily linked (source effect) amplified enhanced inland rainfall Holocene. During LGM, low at likely due ground-temperature effect composition, possibly associated steeper altitudinal thermal gradient inland, air mass trajectories over Sea.