Tor topography in Giresun mountains, Türkiye

Abstract

Tors are mound-like rock landforms, resistant to erosion, that may sometimes reach the size of several storeys of house by volume. They may develop in different climate regions and different rock types, led by granitic rocks. In this study, tors developed in granitic rocks around Yaylalı village linked to Kürtün county in Gümüşhane were investigated. The study area is located in the eastern part of the Giresun mountain range in northeastern Turkey, 2000–2300 m above sea level. The aim of the study is to determine the natural environmental characteristics in tor formation and to reveal the effect of bedrock on tor formation. During field studies, 18 tors were selected by noting location, size and structural features, and dimensions were measured. Thin sections were first made from the rock samples taken from the tors and then the mineralogical composition was investigated by modal analysis method. As a result of this analysis, it was determined that the bedrock forming the tors is granite. During the field observations, it was determined that the intersecting vertical joints supported the formation of castle-like tors, while the horizontal joints supported the formation of pita pile-shaped tors. There are also pseudokarstic shapes resembling kamenitza and karst pavement. In conclusion, joint sets causing local resistance differences directed the formation of tors, while excess slope affected surface erosion and suitability of climate conditions-controlled weathering rate. © 2023, Science Press, Institute of Mountain Hazards and Environment, CAS and Springer-Verlag GmbH Germany, part of Springer Nature.