RT - Journal Article T1 - Genesis and Micromorphology of Saline and Gypsiferous Aridisols on Different Geomorphic Surfaces in Nough Area, Rafsanjan JF - JCPP YR - 2003 JO - JCPP VO - 7 IS - 3 UR - http://jcpp.iut.ac.ir/article-1-445-en.html SP - 71 EP - 93 K1 - Gypsiferous soils K1 - Aridisols K1 - Micromorphology K1 - Geomorphology K1 - Central Iran K1 - Rafsanjan AB - Gypsiferous Aridisols are of great importance and extent in arid and semi-arid environments. There is a close relationship between soil genesis and landscape positions. This study aimed to determine the genesis and classification of gypsiferous soils and to investigate the relationship between micro-and macro-morphology of gypsum crystals and geomorphic positions in Rafsanjan area. The study area is located in Nough, 30 km north of Rafsanjan with a mean annual precipitation of 60 mm. Seven representative pedons were selected on different geomorphic positions. Physico-chemical, micromorphological, XRD, and SEM observations were performed on soil samples. Rock pediment geomorphic surfaces, that are in fact peripheries of old closed water bodies in central Iran, are the source of gypsum in the area. Large gypsum pendants and microforms of lenticular, vermiform, platy, and interlocked gypsum plates are found in rock pediment. The amount of gypsum and the size of pendants decrease moving down the slope. Lenticular and interlocked gypsum plates are found in a transition of pediment and playa. Puffy ground is observed on the saline surface of playa. Lenticular and vermiform gypsum crystals increase down the slope, but alabastrine gypsum is the most dominant form of gypsum in the playa surface. Large amounts of soft gypsum nodules are found on the rock pediment surface (western slope). In addition, spindle form of gypsum and palycrete bundles are observed in this position. Wind action played a significant role in the genesis and development of soil in rock pediment. A close relationship was found between morphology of gypsum crystals and geomorphic positions. LA eng UL http://jcpp.iut.ac.ir/article-1-445-en.html M3 ER -