آثاری از تغییر آب و هوای دیرینه کواترنر موجود در برخی پارینه خاک‌های دو منطقه اصفهان و امام‌قیس چهارمحال و بختیاری

Investigation of paleosols plays a great role in paleoecological and paleoclimatological studies. They are also important in soil survey and planning, as they exhibit characteristics different from younger soils. Paleosols are those soils which formed under conditions different from present ones, and are either buried within sedimentary sequences or those which lie on persisting surfaces. Although such soils are widespread in central Iran and Zagros Zone, they have not been studied adequately. Paleosols are identified by different parameters such as morphological, physical, chemical, mineralogical, and micromorphological characteristics. In this study, morphological, physical, and chemical properties of three paleosols from Isfahan and Chaharmahal & Bakhtiary provinces were investigated. The profiles were on different landforms including alluvial fan, dissected old plain, and old lagoonal deposits. Soil profile in Segzi site, on old lagoonal deposits, had a very dark and thick layer at a depth of 45-60 cm containing some macrofossil shells. This shows that this area was covered by brackish water during the early Holocene. In Sepahanshahr profile, presence of strong clay coating and high concentrations of CaCO3 indicates a wetter environment in the past than the present conditions with a precipitation of only 100 mm. In Emam-Gheis profile, a buried paleosol was identified with strong clay coating and free CaCO3 horizons that shows more humid conditions. Evidences obtained from the three paleosols studied indicate that effective moisture in central Iran and Zagros regions during Late Pleistocene had been higher than its present levels.