SPELEO-GEOMORPHOLOGICAL AND GEOPHYSICAL INVESTIGATIONS IN THE SOUTHERN PART OF THE ASKHI LIMESTONE MASSIF, GEORGIA, CAUCASUS

Abstract

Georgia is a mountain country, located in the Caucasus region, where carbonate rocks are frequent and geographically well-distributed across the country. The aim of this paper is to introduce the main results of speleo-geomorphological and geophysical investigation conducted in the southern part of the Askhi Limestone Massif (namely Turchu Limestone Polje). Based on the complex studies, karst forms such as sinkholes and ponors were identified, the width of the Quaternary deposits located on the limestones was determined, the average and maximum discharges of the streams flowing on the bottom of the polje were calculated. The closed shape of the Turchu limestone polje and the limestone bottom covered with Quaternary sediments indicate the corrosive origin of the polje, which has been practically confirmed by our georadiological and electrometric studies. It seems that the evolution of the polje is actively taking place in the limestones under the Quaternary sediments and the dissolved material was being removed and is still being done through underground karst ways (underground corrosion). It is notable that the role of tectonic movements in the origin of the polje along with the corrosive processes, which had a periodic character and together with the uplifting of the area caused the lowering of the levels of underground waters and, consequently, the activation of karst processes.