Temporal Changes in Radiocarbon Reservoir Age in the Dead Sea-Lake Lisan System

Abstract

The Holocene Dead Sea and the late Pleistocene Lake Lisan were characterized by varying radiocarbon reservoir ages ranging between 6 and 2 ka in the Dead Sea and between 2 ka and zero in Lake Lisan. These changes reflect the hydrological conditions in the drainage system as well as residence time of 14C in the mixed surface layer of the lake and its lower brine. Long-term isolation of the lower brine led to 14C decay and an increase in the reservoir age. Yet, enhanced runoff input with atmospheric 14C brings the reservoir age down. The highest reservoir age of 6 ka was recorded after the sharp fall of the Dead Sea at approximately 8.1 ka cal BP. The lower reservoir age of zero was recorded between 36 and 32 ka cal BP, when the Lake Lisan mixed layer was frequently replenished by runoff.