Silt heaving and the origin of the Azraq basaltic soil

Three pits are dug throughout the soil profile (about 1 m) below the basaltic loose veneer rubble to the basaltic bedrock demonstrating sharp contacts between the soil and the basalt below and above. Non of the basaltic rubble fragments are present within the soil profiles. The yellowish-reddish soil consists mainly of silt size carbonate, basaltic rock fragments, quartz, feldspar, slightly altered olivine and/or pyroxene, in s ita gypsum, and clays. The clay minerals present are kaolinite, illite/smectite mixed layers, and palygorskite. The major elements of the soil samples are explained by two phases: a basaltic phase and a carbonate phase. Because of the sharp contacts with the basalt and its fresh nature, the well-rounded components of the soil, the non-presence of basalt cobble and boulder size fragments within the soil, and the immature nature of the soil, we advocate that this soil originated through wind blown and accumulation of silt size materials called here silt heaving. (authors). 27 refs., 12 figs., 3 tabs