Calcic horizon distribution and soil classification in selected soils of north-western Jordan

Calcic horizons are formed in most of the soils in northern Jordan where a dry, warm climate prevails. Soil samples were collected from four soil sites representing different parent material types (colluvium, alluvium). The purpose of this study was to discuss the possible genesis of calcic soils in north-western Jordan and to classify these soils according to the USDA soil taxonomy. Calcium carbonate accumulations in the studied soils varied from slight carbonate filaments to prominent stage II and stage III carbonate nodules and plugged horizons. Carbonate and clay eluviation-illuviation were the dominant pedogenic processes in the study area. These soils developed in a humid climate that shifted gradually towards aridic.