Yarim-Ghayeh Cave(Study and Investigation)

Yarim-ghayeh cave, located in the border of Iran and Turkey, is hosted by the Oliogocene-Miocene limestone body. Its in and outside rough topography implies that the cave is very young and infact in the beginning stage of its formation. Overall volume is 9600 m3 with 631 m2 dry area and 4700 m3 occupied by water with 4 to 6 meters in depth. Structurally, the cave has been formed by a fault system cause a sinkhole form on the top of the cave aproximately of 10000 m2. Its water is clean and clear with pH of 7.36 and its fluorine is only 1.7 ppm compared to 4.5 ppm in Maku area. Yarimghayeh playa with an area of 5 m2 is in the close eastern part of the cave with permenant water flow. Elevation of the water surface of playa is 1414 m which is 2 m higher than the water surface of the cave (1412 m). 500 m3 water is daily pumped out without any change in water level. Since there is no any other water flowing to the cave, therefore, the playa is supplying the cave water system. The ecosystem of the cave and playa are tight together and any change in one will affect the other. To protect its water quality from contamination, access to this small scale cave must be restricted except for scientific research.