Palynological evidence for the Quaternary rates of accumulation along the Dead Sea Rift, and structural implications

Continuous pollen diagrams obtained for five deep boreholes penetrating the thick Quaternary sector of the Dead Sea Rift fill have been correlated with the oceanic oxygen isotope records. One of these was radiometrically dated by interfingering volcanics. The Quaternary sequence was subdivided into ten palynozones, and the rates of accumulation are calculated for each, in the three sub-basins of the Dead Sea Rift. Rates of accumulation in increments of 100 ky are calculated for two boreholes, Notera 3 in the north and Amazyahu 1 in the south, based on more detailed data obtained for these sequences. The rates of accumulation indicate considerable subsidence of the southern Dead Sea at 2.3-1.8 m.y., during the last 250 ky; the northern Dead Sea in the last 20 ky; the central Jordan Valley at 2.2-2.0 m.y.; and the Hula at 1.5-1.25 m.y. and during the last 70 ky. The regions separating these sub-basins show very little accumulation and subsidence through the Quaternary. It is evident that the structural development of the Dead Sea Rift sub-basins is not synchronous.