Climate-induced specific features of desertic pedogenesis in Northern Libya

The climatic parameters (precipitation, temperature, pressure and wind regime) that determine the nature of desert soil formation and the formation of hamads, soils of different genesis and soil cover structure in Libya are analyzed. The atmospheric processes play an important role on the general background of arid conditions. For most of the year, high atmospheric pressure forms over the Sahara, which determines the direction of the winds to the Mediterranean coast, where deep cyclones create a pressure gradient during the cold season and catalyze the formation of strong winds in the highlands of Ahaggar and Tibesti located in central Sahara. Sticking to the slopes of uplands and stupene-like surfaces of hammads, the wind turns into a fan - a powerful factor of denudation of bedrock and formation of a rocky-gravelly surface of hammads, as well as aeolian accumulation along their periphery. Studies of soils and soil cover patterns in the alluvial-proluvial plain revealed the formation of gray-brown deserted slightly differentiated carbonate soils (Skeletic Gupisisols (Hypergypsic)) and lithoses (Hyperskeletic Leptosols (Yermic)), which in combination form a lithogenous microstructure. On the Hamada al-Hamra plateau, the dominant type is the gray-brown desert carbonate soils (Salcic Gupisisols (Yermic)) with a reddened reddish horizon in the middle part of the profile. The microstructure is represented by a low-contrast combination of soils of different power - a tachet. Differences in the formation of the cortical horizon and the "deserted bridge" gray-brown soils of boreal soil-forming conditions with subtropical and tropical were revealed. Because of the intense wind regime in the soils of Libya's hamada, the cortical horizon is less dense and powerful.