Volcanic tuff as a World Heritage Georesource, a Case Study of Tokaj Wine Region UNESCO Cultural Landscape

Abstract

Volcanic tephra and pyroclastic rocks are common georesources worldwide. Volcanic eruptions produce these materials, and the freshly deposited volcaniclastic sediments undergo variable diagenesis and possible hydrothermal alteration. The rhyolitic pyroclastic rocks of the Carpathian Basin were formed as a result of major silicic volcanism during the Miocene and are exposed in several volcanic regions. The use of these stones depends on their physical properties, such as hardness, colour, and transportability, especially in masonry and ornamental design. The study site, the Tokaj Wine Region (TWR) Historic Cultural Landscape is a UNESCO site located in NE Hungary, which was inscribed on the World Heritage List in 2002. The silicic pyroclastic rocks, here we also referred to them as rhyolite tuffs, are significant geological resources in the UNESCO cultural heritage designation. The pyroclastic formations cover an area of about 100 km2 and were deposited by three major explosive eruptions (13.1–11.5 Ma). The local varieties are defined by primary volcanological features and secondary (diagenetic, hydrothermal) effects. The stone was extracted from more than 40 open pit quarries dating from the Middle Ages. The wine cellars and dry-built terrace walls are important cultural features of the volcanic tuff use. The geoconservation value of the rhyolite tuff is well illustrated by the exposed special geological features, which represent important sites of volcanic formations. However, only one site has been declared a nature conservation area. Several historic quarries are currently abandoned, and there are many problems due to the lack of their restoration. The most common problems are the instability of quarry walls, illegal dumping, pollution, and dense vegetation covering the geological values. The volcanic tuff has a great potential as a georesource (quarries, cellars, and terrace walls) adding value to World Heritage Site, but special efforts are needed to demonstrate its potential for geoconservation, geotourism, and geo-education.