Development of Periglacial Landforms and Soil Formation in the Ilgaz Mountains and Effect of Climate (Western Black Sea Region-Türkiye)

Abstract

The main aims of the current study are to determine the morphological features of the periglacial landforms (non-sorted step, mud circle, stony earth circle, thufur, and congeliturbation) located on the Ilgaz Mountains, examine the physicochemical and mineralogical properties with pedological processes of the soils, and assess of the effects of climatic conditions controlling the development of landforms. The Ilgaz Mountains (2587 m a.s.l.), located in the Western Black Sea Region, within the Anatolian Mountains, are important in terms of periglacial landforms (mud circles, stony earth circles, thufurs, non-sorted steps, non-sorted stripes, congeliturbation deposits, and block currents). The descriptive statistics of 123 periglacial landforms measured by fieldworks were analyzed. The distribution of freezing and thawing in the Ilgaz Mountains throughout the year was evaluated, and it was found that freezing takes place between December and March, freezing-thawing takes place in April, May, October and November, and thawing takes place between June and October. Accoding to soil properties, organic matter content changes from 1.88% to 12.72% in non-sorted step soils, while it is between 2.03% and 12.24% in stony earth circle soils. The organic matter is observed to be close to congeliturbation deposits at lower ratios compared to non-sorted steps, stony earth circles and mud circles. The soil reactions on stony earth circles and non-sorted steps vary between slightly acidic and slightly alkaline. On the other hand, soil samples taken from the mud circles are different from those taken from the non-sorted steps and stony earth circles. Their soil reaction is acidic, and pH changes between 4.86 and 6.25. The lime content also varies between 2.81% and 32.08%, with an average of 12.02%. The texture properties of soils are dominantly loam and clay loam, as in the non-sorted steps, stony earth circles, and mud circles. Considering their mineralogical properties, the XRD study was carried out to determine the primer mineral types and abundance degrees of soils of periglacial landforms. Quartz, muscovite and albite minerals were found in soils in the stony earth circle, while quartz, muscovite, orthoclase and albite minerals were determined as primary minerals in soils formed on the thufur landforms.