The late Pleistocene climate of Israël / Le climat au Pléistocene récent en Israël

Abstract

Pollen diagrams obtained from several boreholes in Israel, and pollen analyses of prehistoric sites and strata covering the time span equivalent to the last Interglacial through the last Glacial maximum in Europe serve to delineate the climatic history of the country. The recurrence of paleoclimatic trends in several basins and in different environments ensures than the results reflect the regional climate rather than local conditions. The dating of the analyzed sequences is based on radiocarbon in the upper parts and on correlations with uranium-series and potassium/argon dates obtained for outcrop material in the older strata. The last Interglacial, locally referred to as Interpluvial, is characterized by very low percentages of arboreal pollen, lower than the present day values, which seem to indicate a very poor rain regime of rare thunderstorms, allowing only little water available for plantlife and resulting in severe erosion. This type of climate, with minor fluctuations, persisted in Israel from some 125,000 years up to some 80,000-70,000 years ago. The last Glacial, locally termed Pluvial, is typified by rich arboreal pollen spectra, where the AP takes a considerably higher share than at present, indicating a rain regime different than at the preceedtng interpluvial or the succeeding Holocene. The present day, with typical winter thunderstorms and a moderate vegetation cover is regarded as an interstadial climate. A paleoclimatic model is presented, in an attempt to explain the three main climatic regimes of the late Quaternary.