The Slanské vrchy Mountains are one of the most interesting geological areas of eastern Slovakia. At first glance, it looks peaceful - forested ridges, deep valleys and inconspicuous peaks. But beneath the surface lies a dramatic past. This land was made of fire.
The Slanské vrchy are part of the Vihorlat-Gutín volcanic area, which was formed approximately 16 to 9 million years ago in the younger Tertiary (Miocene) period. At that time, the area of today's eastern Slovakia was tectonically very active.
From the depths of the earth, magma rose, which, when cooled, formed the typical volcanic rocks - mainly andesites and rhyolites. Andesite is nowadays the dominant rock of the Slanské Hills. It is resistant, strong and forms characteristic rock formations and steep slopes.
The eruptions were not one-offs. Volcanic activity occurred in several phases, from lava outpourings to explosive eruptions that produced tuffs and pyroclastic layers. The result is a relief that has softly sculpted ridges but also, in places, prominent rock ridges.
One of the most precious gifts of this volcanic past is opal. In the area of today's Opal Mines, unique conditions were created for the formation of precious opal.
The process of creation was slow and took thousands of years. After volcanic activity subsided, hot hydrothermal solutions rich in silica penetrated the rocks. This gradually deposited in the rock fissures and formed layers of opal. The combination of chemical composition, pressure and temperature gave rise to the so-called precious opal with its typical play of colours.
In the 18th and 19th centuries, Slovak opal was a world unique - it adorned noble collections and imperial courts. At that time, the Dubnica mines were the only known significant source of precious opal in the world.
The volcanic origin influenced not only the rocks but also the nature of today. The mineral composition of the soils supports specific vegetation and biodiversity. The forests of the Slanské Hills are predominantly beech and oak, with fir mixed in at higher altitudes. The volcanic bedrock also creates natural springs and stable microclimatic conditions.
The relatively soft landforms are the result of long-term weathering of volcanic rocks. Millions of years of erosion have softened the sharp shapes of the volcanoes and created today's ridges, which look serene - but the underlying drama is dramatic.
The Slanské vrchy mountains today do not look like a land of fire. They are a land of silence, forests and prospects. But their geological story is still legible - in the structure of the rocks, in the andesite rocks and in the underground tunnels.
Every trip to this area is actually a journey millions of years into the past. The landscape we admire today was formed from explosions, lava and hot solutions. And it is because of this past that the Salzkammergut has its unique identity - raw, authentic and unrepeatable.
Author: the Regional Tourism Organisation Región Šariš
Author of the photo: Regional Tourism Organisation Región Šariš
