Weathering Rates and Some Physico-Chemical Characteristics of Soils Developed on a Calcic Toposequences

Abstract

Soil formations were highly associated with topographic positions which have influence on morphological, mineralogical and weathering process of the soils. Because, topography or relief affects how water and other material are added to and removed from soils. The aim of this study is to carry out apedological assessment of the soils classified as Regosol, Cambisol and Vertisol by taking into considerationFAO classification system formed on different topographic position and the same parent rocks (limestonemarl).In addition the second aim of this research is to answer the question about the difference in classificationresulting from pedogenic processes or from other factors by determining the degree of weathering soils usinggeochemical data. For this aim, after macro-morphological identifications were completed for threerepresentative soil pedons, the soil samples were then collected from the horizons to investigate the analyticalcharacteristics such as mineralogical, geochemical and physio-chemical properties. The study will also takeinto account other features such as the pedogenic evolution of soils using weathering indices such as CIA,CIW, Base/R<inf>2</inf>O<inf>3</inf>, WIP and PIA. According to results, CIA, CIW, PIA and WIP index values of all soils variedbetween 66.75-73.87, 73.48-81.79, 57.60-68.49, respectively. In addition it was found that the bases/R<inf>2</inf>O<inf>3</inf> values of most of the soils were below 1.0. The results clearly showed that topographic condition stronglyaffects on soil physic-chemical, mineralogical and morphological properties either directly or indirectly in thelocal region. This case was also explained with chemical weathering indices in this study.