Toposequence of sandy soils in the northern coastal plain of Israel: Polygenesis and complexity of pedogeomorphic development

Catenary relationships of surface soils in the vicinity of kibbutz Shomrat in the Galilee coastal plain of Israel were studied including optically stimulated luminescence (OSL). The research provides new insights into the local pedogeomorphic history and confirms that the study area is of different age than the central coastal plain of Israel. The soil toposequence is composed of polygenic red Hamra (Rhodoxeralf) on the hilltop, a calcareous Rhodoxeralf (Husmas) on the middle slope, both older than 250 ka, and a complex pedosedimentary sequence in a lower position spanning Middle Pleistocene–Holocene OSL ages. The hilltop red Hamra is strongly reworked by soil burrowing animals, magnetically enhanced, and contains aged clay coatings and a few petrocalcic nodules. Micromorphology revealed a relict nature of cemented carbonate nodules and allowed us to establish a sequence of pedogenic episodes, e.g. rubification and clay illuviation that intermittently affected nodule growth and re-crystallization. All soils are dominated by interstratified illite–smectite, whose amount and expandability increase downhill. In the lowest topographic positions, soil development was compounded by additional fine-grained accumulation via eolian and slope processes which may have intensified during periods of geomorphic instability. Our data and interpretations suggest that to the north of Haifa Bay, coastal geomorphic surfaces are formed by late Mid-Pleistocene exhumed paleosol toposequences, which are sporadically overprinted by younger paleosols, and continue to function as presently active soils.