10Be in Lake Lisan sediments -: A proxy for production or climate?

The geochemical behavior of Be-10 in the modern Dead Sea hydrological-limnological system was studied in order to evaluate the feasibility of using Dead Sea and Lake Lisan (the late Pleistocene precursor of the Dead Sea) sediments as archives of the variations in the Be-10 production rate. Be-10 concentrations in detrital and aragonite material from Lake Lisan laminated sediments were compared to those measured in modern dust, terra rossa soil (aeolian in origin), loess from the Negev Desert, flood suspended load and waters along a rain-flood development pathway (the transition from rain to incipient runoff and fully developed floods). Be-10 concentrations decreased throughout the flood development profile, from 8.2 x 10(3) atoms g(-1) in the runoff down to similar to 1 x 10(3) atoms g(-1) in Dead Sea brine due to fast removal of Be-10 by the soil and dust particles. Thus, most of the Be-10 in the lake is contained within the detrital sediments that collect the Be-10 transported by particles from the surrounding terrain (e.g. desert dust with 1.6 +/- 0.8 x 10(8) atoms g(-1) and terra rossa soil-material with up to 12.5 +/- 0.5 x 10(8) atoms g(-1)).