Micromorphology and Clay Mineralogy Comparison of Paleosols and Modern Soils in Jiroft Area

Paleosols provide invaluable data on paleoclimatic conditions of the area. These soils widely exist in central Iran. Micromorphology and clay mineralogy are among valuable techniques which are useful for interpretation and identification of these soils. The present research was performed to compare the micromorphology and clay mineralogy of paleosols and modern soils of Jiroft area. After field studies, 4 pedons (located on different geomorphic surfaces including stable mantled pediment, stable and unstable transitional surfaces of pediment and alluvial plain, and stable surface of alluvial plain) were sampled for physicochemical, micromorphological, and clay mineralogical analyses. Clay coatings in argillic horizons of paleosols were found during micromorphology observations. On the other hand, clay coatings in present soils were only found in natric horizons, which were attributed to high amounts of Na in these soils. Moreover, smectite, palygorskite, illite, chlorite, and kaolinite clay minerals were recognized in paleosols, but chlorite was not detected in modern soils. The presence of palygorskite in the soils under study was related to the stability of geomorphic surface. Results of the present research showed that a more humid climate was present at the time of paleosols formation.