Volcanogenic encrustations

Volcanogenic encrustations that form during or after subaerial volcanic eruptions in Iceland are collected and analysed, using X-ray diffraction method and scanning electron microscopy. Volcanogenic encrustations form crusts on the surfaces of lava and scoria, in lava caves and cavities, and around crater rims. Most encrustations are deposited as a solid phase from a gaseous state, as volcanic gases rise up through cavities in the cooling rock. Others form by evaporation of a liquid phase, particularly in lava caves and craters. Encrustations are frequently loosely coherent and water soluble, making them susceptible to water and wind erosion. They rarely last long, except in caves. Timely fieldwork at eruption sites is thus necessary to gather newly formed encrustation samples before they vanish. Emphasis has been placed on analysis of encrustations from the 1947–1948 Hekla eruption, the 1961 Askja eruption, the 1963–1967 Surtsey eruption, the 1973 Eldfell eruption, the 1991 Hekla eruption, the 2010 Fimmvörðuháls eruption, and the 2014–2015 Holuhraun eruption.

Balić-Žunić, T., A. Garavelli, S.P. Jakobsson, K. Jónasson, A. Katerinopoulos, K. Kyriakopoulos and P. Acquafredda 2016. Fumarolic Minerals: An Overview of Active European Volcanoes. In Nemeth, K., ed. Updates in Volcanology: From Volcano Modelling to Volcano Geology, pp. 267–322. Rijeka, Croatia: InTech. DOI: 10.5772/61961.

Sveinn P. Jakobsson, Erik S. Leonardsen, Tonci Balic-Zunic and Sigurður S. Jónsson 2008. Encrustations from three recent volcanic eruptions in Iceland: the 1963–1967 Surtsey, the 1973 Eldfell and the 1991 Hekla eruptions (PDF, 10 MB). Fjölrit Náttúrufræðistofnunar no. 52. Reykjavík: Náttúrufræðistofnun Íslands.

IINH Contact: Kristján Jónasson