Investigations of short-term denudation rates on the North Dalmatian Plain (Croatia)

Abstract

[EN]Studies of denudation rates in carbonate areas are an important step to understand rates of karst landscape development. Weathering of carbonate rocks is an essential process in soil formation and has a significant role in the global CO2 budget. We studied short-term weathering and denudation rates at a location in the Dinaric karst using the rock tablet method while monitoring surficial and soil environmental parameters. We exposed “standard” rock tablets and those from local lithologies to the natural environment at the surface and buried them at two depths (20 and 50 cm) in the soil profile. Our results show that the average actual denudation rate measured at this site is 2.28 μm/a (for rock tablets exposed at the surface and buried in the soil). Furthermore, this rate is higher at the surface (2.95 μm/a) than those recorded in the soil (1.46 μm/a and 1.99 μm/a at 20 and 50 cm depth, respectively) and is dominated by physical weathering processes driven by diurnal temperature cycles. On the other hand, weathering of rock tablets buried in the soil profile is dominated by chemical weathering processes strongly dependent on the availability of CO2 in the soil, resulting in higher denudation rates deeper in the soil profile. Furthermore, the denudation rate strongly depends on lithology; thus, local lithologies should be used to obtain actual denudation rates.