Naslov
Development of columnar jointing in albite rhyolite in a rapidly cooling volcanic environment (Rupnica, Papuk Geopark, Croatia)

Autori
Balen, Dražen ; Petrinec, Zorica

Izvornik
Terra nova (0954-4879) 26 (2014), 2; 102-110

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
albite rhyolite; columnar jointing; constitutional supercooling; thermal contraction; Rupnica Papuk Geopark

Sažetak
The Rupnica locality became the first protected geosite in Croatia in 1948 due to a well-exposed phenomenon of columnar jointing developed in albite rhyolite. According to the geochemical signature, melt that originated from mid-crustal depths (10-15 km) reached a shallow emplacement level as a high-temperature lava. Non-destructive statistical analysis conducted at the geosite revealed that relatively narrow (29.4±6.3 cm), predominantly four- and five-sided columns, tightly packed striae (4.8±2.1 cm) and small amplitude of wavy sets of columns (wavelength of 32.5±6.7 cm) dominate the exposed part of the Rupnica. A number of features quantified through such statistical approach, together with petrography, geochemistry and the geology of the geosite surroundings, gave an idea about the rapid cooling of a (sub)surface acidic lava body and the behavior of the evolving volcanic system, developing columnar jointing under the combined influence of large scale constitutional supercooling and thermal contraction processes.

Izvorni jezik
Engleski

Znanstvena područja
Geologija

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