Karatay (Konya) İlçesinde Kuvaterner Yaşlı Hotamış Formasyonu İçerisinde Meydana Gelen Obrukların İlk Bulguları

Abstract

Konya Closed Basin (KCB) is approximately 42.000 km2. The Konya Graben located at east of the Konya settlement area, is controlled by the Konya fault zone in the west, the Karaömerler Fault Zone in the north, and the Divanlar - Göçü faults in the east. Konya region has been under the influence of the lacustrine regime since the Late Miocene period. Konya region has been deprived of today's surface wetlands under the influence of the arid climate regime for the last 12.000 years. In addition to the ongoing drought in the KCB, the groundwater table has decreased by approximately 45 meters in the last 20 years due to excessive and uncontrolled use of agricultural water. The wetlands and swamps in the immediate vicinity of the study area, as well as the last wetlands in the region such as Akyay Lake and Hotamış Lake in the south of the region, have completely dried up in the last 50 years. In the Karatay (Konya) region, there is the Late Miocene-Early Pliocene aged İnsuyu formation, which consists of intercalations of limestone, clayey limestone and marl-mudstone with clastic intercalations at the bottom. On top of the İnsuyu formation, sandy, silty clay and mudstones containing carbonate intercalations from Küpbasan, Sazlıpınar and Bataklık members of the Quaternary-Holocene aged Hotamış formation unconformably overlie. Sazlıpınar member of the Hotamış formation consists of mudstone-marl- and gypsum intercalations. In the Karatay-Aslımyayla region, the sinkholes were formed in relation to the SAzlıpınar member of the Hotamış formation and the voids and karstic voids developed within the İnsuyu formation. Sinkholes are generally 2-30 meters in diameter and 20 cm-6 m deep. The formed sinkholes are generally circular and oval in shape. The sinkholes observed in the Karatay-Aslım private organized industrial campus are in the form of sagging of maximum 0.2-2 m in sandy silty formations. It is observed as subsidence at 2-6 m depths in marl-mudstone-dominated areas in the eastern part of the formation. The sinkholes in the region are formed under the control of the intra-basin surface fissures that develop parallel to the Konya fault zone. It is thought that these rifts probably formed in relation to buried active faults. The rifts are observed for kilometers in the region. There is intense industrial construction in the region and deformations such as sinkholes, collapses and surface cracks in the region should be investigated in detail.