Postojna Cave - Yam

The dissolution of limestone begins on the ground, in one place more strongly in the other weaker, so some form of the valley (sometimes, however, they arise from the collapse of the caves). But where the water gets access down through fissures, and dissolution begins at a depth of: formation of caves. Therefore the direction of the cavities are often predetermined strike cracks or bedding planes of limestone. So, the plan Postojna Caves - Yam reflects the north - western ("RSD") stretch of folded limestones of Cretaceous age, as well as the direction perpendicular to the strike of this fracture. More than the giant size of the individual "rooms" caves (which are in low light seem monstrous), visitors struck by the splendor of the most diverse form of sinter. Thousands and thousands of stalactites hang like a curtain from the ceiling of the cave something as thin as a pencil, then thick as a column, a length of several meters. More often than in other caves in Postojna - Pit can be found wandering the form, "opposite" stalactites, stalagmites, which grow from the bottom of the cave up. Stalagmites more massive, but at the same time have a more elegant sculpture. (Almost the same name "stalactite" and "stalagmite", denoting the different forms patechnyh entities that originate from the same Greek word stalagma, which means "drop"). Stalagmites reach 1 m or more in thickness and several meters in height. Both types of "beak" formed as a result of the fact that the rich lime dripping water contained in the drink loses CO2 and evaporates, and lime (CaCO) is deposited either on top, on the ceiling of the cave or the bottom, the bottom of the PA. In other words, stalactites and stalagmites grow towards each other. Their rate of growth is very different. Experiments in Postojna - Yam showed that each year stalagmite deposited from 0,2 to 2 kg of lime (calcite). At one of the bridges over the river Pivka for 20 years formed stalactites as thick as a pencil and a length of 10 cm Sometimes there collapsed stalagmites. Before their collapse associated with earthquakes, but more likely the assumption that the stalagmites are falling, if the reason they are not always steady, blur suddenly broken through water. The formation of caves began to - apparently at the end of the Tertiary period, ie only a few million years ago, but the majority of cavities appeared likely in the period of glaciation. The processes zakarstovyvanii penetrated deeper and deeper. River beer, "diving" into a mountainside near the entrance to the cave, now flows is seen in some places, below the level of dry caves with stalactites, which tourists visiting the part with the little trains of the underground road, part of the foot. Initially, as the river flowed over the surface of the earth toward Plapiny. One look na ceiling of the cave is sufficient to establish that the location of the stalactites is also associated with cracks in some places, they form a series, as the water dripping from the ceiling supports the cracks. In addition to stalactites and stalagmites, the cave walls are visible na sinter in the form of sheets, and sometimes also gathered in soft folds fringe, nodding to the ceiling like a canopy, so thin and transparent that it effectively illuminated from behind.