K-Ar and Rb-Sr geochronology and evolution of the Štiavnica Stratovolcano (Central Slovakia)

Year, pages: 2013, 327 - 351

The Štiavnica Stratovolcano in Central Slovakia is the largest volcano in the Neogene to Quaternary Carpathian volcanic arc. A large caldera, an extensive subvolcanic intrusive complex and a resurgent horst with late stage rhyolite volcanites are the most characteristic features. The results of new K-Ar and Rb-Sr isotope dating using more sophisti- cated methodical approaches have changed our view on the timing of volcanic and intrusive activity. K-Ar dating of groundmass fractions combined with Rb-Sr isochron dating in the cases of possible rejuvenation has provided highly reliable results. The lifespan of the stratovolcano is apparently shorter than assumed earlier. Evolution of the stratovol- cano took place in five stages during the Early Badenian to beginning of Early Pannonian time: (1) construction of the extensive andesite stratovolcano during the interval 15.0—13.5 Ma; (2) denudation of the volcano concluded with the initial subsidence of a caldera and the contemporaneous emplacement of a subvolcanic intrusive complex of diorite, granodiorite, granodiorite porphyries and quartz-diorite porphyries during the interval 13.5—12.9 Ma; (3) subsidence of the caldera and its filling by differentiated andesites during the interval 13.1—12.7 Ma – volcanic activity overlapping with the emplacement of the youngest intrusions; (4) renewed explosive and effusive activity of less differentiated andesites during the interval 12.7—12.2 Ma; (5) uplift of the resurgent horst in the central part of the caldera accompa- nied by rhyolite volcanic/intrusive activity during the interval 12.2—11.4 Ma. Extensive epithermal mineralization was contemporaneous with the uplift of the resurgent horst and rhyolite volcanic activity and continued till 10.7 Ma.

Chernyshev, I., Konečný, V., Lexa, J., Kovalenker, V., Jeleň, S., Lebedev, V., Goltsman, Y. 2013. K-Ar and Rb-Sr geochronology and evolution of the Štiavnica Stratovolcano (Central Slovakia). In Geologica Carpathica, vol. 64, no.4, pp. 327-351. 1335-0552. DOI: https://doi.org/10.2478/geoca-2013-0023

Chernyshev, I., Konečný, V., Lexa, J., Kovalenker, V., Jeleň, S., Lebedev, V., Goltsman, Y. (2013). K-Ar and Rb-Sr geochronology and evolution of the Štiavnica Stratovolcano (Central Slovakia). Geologica Carpathica, 64(4), 327-351. 1335-0552. DOI: https://doi.org/10.2478/geoca-2013-0023