Ozaytekin, Hasan HuseyinUzun, CihanKaraarslan, EmelDedeoglu, Mert2020-03-262020-03-2620181018-46191610-2304https://hdl.handle.net/20.500.12395/37063In comparison with Andisols from humid regions, very little information is available regarding the volcanic soils of semi-arid climates. The objectives of this research were to discuss the extent to which these soils meet the requirements of real Andisols, as defined by Soil Taxonomy and to investigate the physical and chemical properties, as well as to define the weathering processes and pedogenic products, of the soils formed over the volcanic materials of Mt. Hasandag in a semi -arid environment. For this purpose, 4 representative soil profiles were evaluated; after morphological identifications were completed, the soil samples were collected from the horizons to investigate the physical, chemical, geochemical and mineralogical properties to analyze the soil formation over time in a semiarid region. The soils also underwent FT-IR and Scanning Electron Microscope (SEM) analysis in the range of 4000 to 400 cm(-1) with pellets and at magnifications ranging from 250 to 20.000 X. The results indicated that the content of the sand and coarse silt fractions were higher than 30% in all soils. Phosphate retention is generally low, and it is lower than 85% in all profiles. The pH values in NaF are lower than 9.5, in general. The bulk density is higher than 0.90 gr.cm(-3) in all profiles. The Al + 1/2 Fe percentages (by ammonium oxalate) are lower than 2% in all profiles. Selective extraction in all of the horizons in profile 5 exhibited the following relationships: Fe-o>Fe-d>Fe-p and in other profiles, and in most horizons, Al-p>Al-d>Al-0 Selective extraction indicated that in contrast to the soils usually forming on volcanic material worldwide, these soils lack noncrystalline minerals, such as allophone, imogolite and iron humus complexes. The only noncrystalline minerals that are present in great quantities are Al-humus complexes and Ferrihydrite. The crystallized Fe minerals were higher than the other Fe minerals. Feldspar (anorthite and albite), amphibole (diopside, Actinolite, tremolite, hornblende) apatite, hematite, olivine and biotite were more common primer minerals. X-ray diffraction indicates smectite, kaolinite and illite were dominant minerals in the clay fraction. Furthermore, a considerable quantity of chlorite-smectite interstrafied was identified in the clay fraction. The results indicated that the dominant soil-forming processes include the following: 1. desilication and the loss of base cations and Al from the solum; and 2. transformation of iron and aluminum from the sand and silt-size fractions into secondary clay and crystalline Fe minerals. The climate, topography and the nature of the parent materials affected by the leaching regime and weathering rates were identified as the major factors determining soil genesis on Mt. Hasandag. The studied soils were not classified as Andisol because of their lack of andic properties.eninfo:eu-repo/semantics/closedAccessAndisolsSoil weatheringSoil FormationSoil ClassificationHasandagArticle272880897WOS:000427344600031N/A