Discovery of specific volcanogenic structures in basaltic rocks of the Faroe Islands

The Faroe Islands (Føroyar) are formed by several thick series of subaerially emplaced plateau basalts of Palaeogene age. During the systematic volcanological survey of the Faroe Islands conducted since 2014, actively participated by Assoc. Prof. RNDr. Lukáš Krmíček, Ph.D. of the Institute of Geology of the Czech Academy of Sciences, unusual volcanogenic structures occurring on the surface of a basaltic dyke located on the Sandfelli mountain ridge (754 m a.s.l.) were discovered. The rock wall of the dyke is covered by a dense mosaic of angular to rounded polygonal convex structures designated as pseudo-hieroglyphs. The discovery of pseudo-hieroglyphs, which probably represent unique examples of a chaotic stage of horizontal columnar jointing developed in basaltic rocks, has been described as a part of a worldwide natural heritage in the recent issue of the Geoheritage journal.