A 250 ka sedimentary record from a small karstic lake in the Northern Levant (Yammoûneh, Lebanon): Paleoclimatic implications

摘要: The Levant, influenced by both the Mediterranean Sea and Saharan–Arabian deserts, is a key region for understanding climatic changes in response to glacial/interglacial boundary conditions that have greatly affected regional hydrology. Here, we present first long-term paleoenvironmental record from northern presently much wetter than southern Levant. Our derives multi-proxy study of sediment core (36 m long) retrieved small intra-mountainous, tectonic basin Yammouneh (Lebanon), which mainly supplied karstic springs.Sediments consist thick accumulation brownish greenish clayey silts, interrupted intervals whitish marls composed CaCO3 rich material. chronology based on radiometric dating (14C U/Th) paleomagnetic techniques. sedimentary sequence spans approximately last two glacial–interglacial cycles (~ 250 ka). Carbonate content relatively high throughout profile due perennial input detrital calcite watershed, but varies significantly. are mostly authigenic biogenic reflect lacustrine environments with carbonate productivity during peaks interglacial periods. Their occurrence suggests low physical erosion slopes were covered arboreal vegetation, intense water circulation under warm wet conditions, agreement pollen data. silts dominated quartz clay minerals, few amounts K-feldspars dolomite. They characterized concentration magnetic particles, relative concentrations Si, Al, K Fe considered as strictly origin. Due carbonated nature attributed eolian origin distal source. silt generally suggest palustrine abrupt flows responsible runoff-derived material, or subaerial local availability particular Last Glacial Maximum. High Si/Al K/Al ratios, interglacials, dust contribution decrease inputs.Our reveals significant differences between lake records Dead-Sea (southern Levant), latter showing high/low levels These hydrological might either North–South (NS) rainfall gradient development ice sheet southward migration westerly belt, factors, i.e., efficient precipitation at coldest glacial periods (e.g., Maximum), storage caps Mount Lebanon range frozen soils basin.