Very few people, while driving on the highway or hiking, are aware of the fact that the surrounding rocks have a rich and diverse history. Unless they are geologists, they are not trained to recognize a certain cliff as a rock formed on the shores of an ancient ocean, a frozen stream of lava, an inactive volcano, a coral reef formed in tropical turquoise seas, or other marvels preserved in stone. We live in a modern, urbanized, industrial world and there is not much time to pay attention to such mysterious beauty and values that could easily be destroyed, but could never be restored again.
Papuk Geopark has a unique position in the collision zone of two tectonic plates – the African plate and the Eurasian plate.
Various types of rocks are found on a small area (magmatic or igneous, sedimentary and metamorphic). They have been created from the Precambrian to the present day. The rocks of Papuk were formed in different geological environments, the consequence of which is the diversity of rocks in terms of lithology, stratigraphic age or structural characteristics. There are rock formations of exceptional geological interest, some of them older than 600 million years, which makes them one of the oldest rocks in Croatia. In geological terms, Papuk is located in the southernmost part of the Tisia tectonic unit which represents part of the pre-Neogene crystalline base of the Pannonian basin.
Papuk is mostly built of metamorphic and magmatic rocks, and the parts of the Tisian tectonic plate found on Papuk are the best examples in the wider area of the Pannonian basin.
Permian-Triassic sediments and deposits of Neogene and Quaternary age lie on the crystalline base. Data on the age of metamorphites (phyllites, chlorite shales, gneisses, migmatites, and amphibolites) and granites are scarce, and their age is a subject of frequent conflict among geologists; they were considered to be of Precambrian age while others classify them as older Paleozoic. The Mesozoic formations are mostly represented by carbonate rocks, in which karst forms are frequent: abysses, sinkholes, caves, pits. They are found in the higher parts of Papuk.
In the Cenozoic, fossiliferous sediments were formed, most commonly in the Miocene age, when Papuk was an island in the Pannonian Sea. During the Miocene, volcanic activity was also common, the evidence of which are pyroclastic deposits and smaller volcanic bodies.
The final tectonic uplift and erosion of the rocks of the Slavonian mountains accumulated large amounts of sediment detritus, which is nowadays preserved as more than 1 kilometre thick sediment of the Sava and Drava depressions.
