Clay Mineralogy Studies of Soils Located on Different Geomorphic Surfaces in Sarduieh-Jiroft Area

Mineralogy، as one of the most important characteristics of soils، varies according to topography. Each clay mineral has unique properties، which influence the overall properties of the soils. The objective of the present study was to investigate soils clay mineralogy in relation to geomorphic surfaces in Sarduieh-Jiroft area. Soil moisture and temperature regimes of the area are xeric and mesic، respectively. Rock pediment، hill، mantled pediment، alluvial plain، and lowland landforms were indentified. Each landform was divided into different surfaces due to geomorphic stability. One representative pedon was studied and sampled on each geomorphic surface. Clay mineralogy analyses were performed on soil samples. The results showed that illite، chlorite، smectite، vermiculite، palygorskite and kaolinite clay minerals were present. Smectite mineral was dominant in the soil of the region as the product of illite and chlorite weathering، and، in lowland surfaces، it had authigenic source. Palygorskite was observed in the stable mantled pediment surface and in calcic horizon. Vermiculite mineral were formed in the lowland due to high humidity of illite mineral transformation. Chlorite، illite، and kaolinite clay minerals seemed to have been inherited from parent material.