Geoheritage and geotourism in the Papuk UNESCO Geopark (Croatia) at its key locality Rupnica - the “First Croatian Geological Monument of Nature”

The area of the Mt. Papuk (eastern Croatia) is characterised by rich biodiversity and historical heritage, but also by an exceptional geodiversity, providing the ground for declaration of Nature Park (NP) Papuk in 1999. However, the uniqueness of certain features has been recognized even earlier as in the case of the Rupnica geosite, which has been declared the “First Croatian Geological Monument of Nature” as early as 1948. In 2007 the geodiversity and geoheritage of Mt. Papuk were internationally recognised which therefore became the first protected area in Croatia to receive the status of a geopark and became a member of both the European and World Geopark Network under the protection of UNESCO.  

Rupnica geosite (NW part of Papuk Geopark, near the town of Voćin) is famous for the well-exposed occurrence of columnar jointing. Although the exposed outcrop is not as impressive in size as some other world-known sites with the same feature, Rupnica is a scientifically valuable geosite as columnar jointing is more commonly developed in basaltic rocks, while the rocks exposed at Rupnica are acidic. The rocks of Rupnica are albite and aegirine-albite rhyolites with porphyritic texture dominated by albite phenocrysts hosted in matrix of albite microliths, quartz and devitrified volcanic glass with accessory minerals (magnetite, apatite, zircon and occasionally alkali clinopyroxene (aegirine-augite)). Volcanic rocks of Rupnica formed by cooling and (near-)surface crystallisation of acidic magma during the Late Cretaceous (~81 Ma) and are related to regional geological events associated with closure of the Neotethys Ocean. Geochemistry points to a parental A-type magma formed in an anorogenic tectonic setting from a lower crustal source with peraluminous, alkali-calcic to alkalic, ferroan and high-temperature (780–900 °C) character. Recent studies of inclusions captured in accessory zircon (i.e. anatase, fluorapatite and hematite) indicates possible mantle source contribution, rapid uplift and cooling of an oxidised magma.

Despite its scientific value, it is mainly the striking surface appearance that makes the Rupnica geosite a trademark of the Papuk Geopark. Nevertheless, both recent and past volcanic activity and associated rocks are usually the main geotouristic attraction and a significant geoheritage. Additional infrastructure and educational facilities recently developed in the Papuk Geopark area, such as the Geo-info centre Voćin (opened in early 2022, only 1 km from Rupnica geosite), enhance geotouristic experience and control visitor access. The now increased number of visitors (~19,000 visitors in 2022, compared to the not precisely known but relatively low number of previous visitors to Rupnica) provides additional opportunities for expansion of local accommodation capacities and touristic offer, contributing to regional economic development. Furthermore, Rupnica geosite is used as an educational polygon for geology students, in primary and secondary science education, but also for the youngest with “Rupko’s School of Geology”, in which the development of columnar jointing is explained in a popular way. The promotional and educational activities of the Papuk Geopark, one of the main tasks of the UNESCO Global Geopark Network, constantly enhance public perception of geodiversity and exceptional geoheritage of the Mt. Papuk area.