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Age relationships between Miocene volcanism and hydrothermal activity at Mt Jarmuta, Pieniny Klippen Belt, West Carpathians, Poland

Birkenmajer Krzysztof, Pécskay Zoltán, Szeliga Wojciech

Studia Geologica Polonica

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2004

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Vol. 123

279-294

EN

In the Pieniny Volcanic Arc (Miocene), the northernmost volcanic arc of the West Carpathians, hydrothermal activity produced some ore-bearing veins associated with moderate-size andesite intrusions. They were subjected to prospecting and mining for gold, silver and lead for a short period at the beginning of the 18th century. K-Ar dating of secondary chlorine-biotite from the mineralized zone at Mt Jarmuta, yielded a K-Ar date of 11.35š0.45 Ma. This K-Ar date fits well with the average K-Ar age (11.34š0.50 Ma) obtained on unaltered andesite sills exposed at Mt Jarmuta. It indicates a close age-relationship between the emplacement of the andesite intrusion and the subsequent ore-mineralization during Miocene (Sarmatian) time.

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K-Ar dating of the Miocene andesite intrusions, Pieniny Mts, West Carpathians, Poland: a supplement

Birkenmajer Krzysztof, Pécskay Zoltán

Studia Geologica Polonica

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2000

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Vol. 117

7--25

EN

Nine sites of the Miocene andesitic intrusions in the Pieniny Mts, Carpathians (Poland), sampled in 1999, were K-Ar dated. The dating was carried out on whole rock, groundmass and monomineral (amphibole) fractions. The present paper completes the K-Ar age study of andesitic intrusions in the Pieniny Mts, the first part of which involving 17 sites was published in 1999. The 1999 samples included both the 1st phase and the 2nd phase intrusions. The K-Ar ages of the 1st phase intrusions, 12.5 to 10.8 Ma, fall within the age range (13.5 to 11 Ma) of the majority of andesitic rocks dated previously. A 2nd phase northern dyke at Mt Wżar (Kluszkowce quarry) yielded the K-Ar whole rock date of 10.8 Ma, the youngest radiometric date recorded from andesitic intrusions of the Pieniny Mts.

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Early Cretaceous K-Ar age of a large basalt olistolith at Biała Woda, Pieniny Klippen Belt, West Carpathians, Poland

Birkenmajer Krzysztof, Pécskay Zoltán

Studia Geologica Polonica

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2000

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Vol. 117

27--35

EN

K-Ar dating of a large basalt olistolith, part of the Upper Cretaceous Jarmuta Formation conglomerate, at Biała Woda, Pieniny Klippen Belt (Western Carpathians), yielded two K-Ar ages: 110.6 ą 4.2 Ma and 120.3 ą 4.5 Ma, from columnar-jointed, and platy-jointed parts of the basalt, respectively. The age difference between these dates might reflect two successive Early Cretaceous volcanic events: (i) platy-jointed basalt being an older event, and (ii) columnar-jointed basalt being a younger one. The basaltic rock discussed was long believed to represent a Miocene intrusion in the Upper Cretaceous Jarmuta Formation conglomerates. The first radiometric dating (1987) of the basalt yielded a K-Ar age of 140 ą 8 Ma (Jurassic-Cretaceous boundary). The present dating refines the age of the basalt at Early Cretaceous (Aptian-Albian), thus confirming its position as an olistolith in the Upper Cretaceous conglomerates of the Pieniny Klippen Belt.