Micromorphological indications on the nature of the Late Quaternary Paleosols in the southern coastal plain of Israel

The nature of alternating layers of clayey soil material and calcareous soil material in the desert fringe area is discussed. In earlier work by other researchers, these soil materials were considered as representing different climatic environments: the clayey layers a wet period and the calcareous layers a dry period. Based on a pedogenic approach supported by micromorphological indications, however, it is concluded that the clayey layers together with the calcareous layers form a single pedogenic unit developed in the same climatic environment. The calcareous layers are in fact calcic horizons accumulated from the overlying leached clayey material and their appearance is similar to the modern Brown Grumusolic soils that occur in the semiarid area of the coastal plain. A sequence of four superimposed Brown Grumusolic paleosols, developed during the last glacial period, was recognized. In the western part of the coastal plain, Quartzic Brown soils and Husmas soils which developed on sand dunes occur. The former has an argilic horizon with a calcic horizon below. Microcalcites of eolian dust origin are homogeneously distributed in the plasma, the soil representing a monogenetic soil type developed during a semiarid climate. The latter is a Reddish Brown Mediterranean polygenetic soil with leached soil material, in which the calcic horizon accumulated from a loessial soil cover that settled during a drier climate. Both soils also developed during the last glacial period. In the eastern coastal plain, older paleosols which developed on sand dunes occur below the Brown Grumusolic soils. One type is a polygenetic leached Quartzic Gray Brown paleosol, not recognized in previous studies, which overlies a Red Hamra soil (sandy Red Mediterranean soil).