Seventy million years ago, what we now call the Țara Hațegului was an intracontinental sea that had at least one island. If the island was the realm of dwarf dinosaurs and giant flying reptiles, the sea was the realm of volcanoes. It was criss-crossed by underwater volcanoes which spurted their lavas over the gravels brought by the inland rivers. Where the sea water was shallow, some of the volcanoes rose above the top of the water, and when this happened, the eruptions became violent. The lava flows typical of the underwater depths disappeared, being replaced by explosions which formed hot clouds of gas and ash. These flowed down along the sides of the volcanoes, entering the sea water tumultuously. Because of the moist air, the ash particles thrown up in the air adhered to one another and formed ash pellets that fell in the shape of hail. While unpredictable and fastidious, the volcanoes that pierced the surface of the sea were ephemeral. Being made up only of ash, once their eruption stopped, the sea would take over. Thus, in only a few months, the waves would destroy the cone of the volcano, sinking it again.
Meanwhile the volcanoes died out and the lava, ash and igneous rocks brought to the surface and set in layers around the volcanoes were moulded by the Earth’s other forms of energy: tectonic plates, which gave rise to the Carpathian Mountains. Compressed, broken and shifted by the earth’s crust on which they formed, the rock fragments rearranged themselves like a tridimensional puzzle. That’s why one can now see pieces from different worlds next to each other: rocks formed on a prehistoric beach and sedimentary rocks formed on the bottom of an ocean.
The traces of the eruptions can be seen today between the villages of Densuș and Ștei, nearby St. Nicholas’ church, on the Route of the Volcanoes and visiting the House of Volcanoes.