Polya

Polya formed by leaching of limestone, however, play an important role, probably, tectonic movements. Anyway, along polya Planina traced reset, long known to geologists. Similarly, this fault line, extending to many tens of kilometers in the north - west direction, there are two polya: often referred to in the literature periodically drying lake Tserknitsa, which can be "fish, hunt and harvest, and Lies Polje, in addition, farther to the north - west on the same tectonic line is known from ancient times Idriyskoe mercury deposits. All the way (and indeed in any karst area) most often seen Valley: funnel-shaped deepening diameter from ten to several tens of meters. Even in a small area can be counted in hundreds. Often, they accumulate a bit of land (sometimes not without a human), and then turns into a tiny valley farmland. All karst phenomena are related ultimately to the fact that - the water can dissolve limestone, however, if it contains carbon dioxide (C02, carbon dioxide). Under the influence of CO - in the limestone (CaC03) is formed by water-soluble compound Ca (S03N) 2. Usually, the limestone in the water practically insoluble. But CO2 is common in nature, it is contained in the air and is formed by decaying plant residues. Dissolution of limestone is very slow, but the gap is 10 or 100 thousand years in the geological time scale is not too great, and is therefore not surprising that in the limestone hills formed the giant cavity, like Postojna - Yam. "Concert Hall of the cave, where the summer's restaurant and post office, reaches a height of 50 m at its" floor "(3000 m2) can accommodate 10 thousand people. The total length of cave passages, including an underground river bed beer, more than 20 km.