An Example of Intracontinental Cross Faults Formation from the Vicinity of Karapınar (Konya – Central Anatolia)

Abstract

Karapınar (Konya, Turkey) is located in the central part of the Anatolian micro-plate which is characterized by differently oriented Neogene–Quaternary horst – graben structures. The basement of the region is composed of Mesozoic–Paleogene rocks. In the various Neogene basins, Miocene–Pliocene sedimentary and volcanic rocks overlie the basement rocks and form the secondary rock units. The youngest units are Plio-Quaternary aged terrestrial sediments and volcanics. The main structure of the study area consists of WNW-ESE and NE-SW trending intersecting graben-horst structures and the normal faults forming them. The approximately WNW-ESE trending basins are filled with Miocene–Pliocene sediments, while the NE-SW trending basins are filled with Pliocene–Quaternary sediments. Kinematic studies show that the faults in the study area are developed in all directions and the distribution of the slicken lines indicates that there is multidirectional crustal extension. The principal stress axes obtained from all the kinematic data show that σ1 is nearly vertical, σ2 and σ3 are horizontal. If all faults are assumed to have been formed due to the same stress system, the study area is predominantly elongated in the NW-SE direction. However, detailed field observations and structural analyses indicate that the NE-SW trending fault systems are younger than the WNW-ESE trending faults. This indicates that firstly NNE-SSW and then NW-SE crustal extension developed in the study area respectively.