קרומי גיר וגבס בקרקע במדבר יהודה - עדויות פדוגניות לזרימה תת קרקעית

Pedogenic features considered to be produced by subsurface flow were observed on the hillslopes of a zero-order basin in the Judean desert where the mean annual rainfall is 230 mm. The basin, some 5000 sq. m in area, is composed of soft chalk covered by soil material, with slope gradients ranging from 30-60 percent. The existence of lateral subsurface flow is indicated on the basis of: (a) Comparison of carbonate, gypsum, and soluble salts distribution within the soil profile to that of other arid environments. (b) Specific micromorphological characteristics of carbonate and gypsic crusts which were not observed in areas where pedogenic features are controlled by limited vertical leaching. The spatial distribution of these pedogenic indicators within the basin and in the soil was analysed in terms of soil water regime, soil thickness, and the permeability of the soil and bedrock.