Abstract

Denudation of carbonate terrains dominated by chemical weathering can be treated as a rain gauge proxy, because the mass lost by dissolution over time is proportional to the time-integrated precipitation. Therefore, the denudation history of carbonate landscapes may provide paleoprecipitation data and shed light on the interactions between climate, denudation, and tectonic uplift. We apply this approach to constrain 104–107 yr average precipitation along the western Dead Sea Rift (DSR) margin, which is underlain predominantly by carbonate rocks and maintains a climatic gradient from Mediterranean to hyperarid along its axis and between its windward and leeward flanks. The comparison between total denudation (from a Turonian datum), denudation rate calculations (from in-situ 36Cl measurements), and present-day mean annual precipitation shows that (1) total denudation correlates with denudation rates and both correlate with precipitation, and (2) over the lifetime of the range (10–20 m.y.), the effective precipitation gradient across the range was higher than at present by at least 40% on average. Along the ∼450-km-long range, the denudation gradient is probably compensated by isostatic uplift. We suggest that along the western DSR margin, and possibly in other carbonate terrains, precipitation (to a threshold precipitation of ∼1000 mm yr–1) controls the long-term denudation rate and the subsequent compensating uplift.

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