Late Jurassic - Early Cretaceous volcanism in the Ukrainian part of the Carpathians

• Autorzy: Krobicki M. , Golonka J. , Malata E. , Oszczypko N. , Słaby E. , Słomka T.
• Konferencja: International Congress on the Jurassic System (7 ; 06-18.09.2006 ; Kraków, Poland)
• Języki publikacji: EN

Abstrakty

EN

Today the Ukrainian Mesozoic volcanic rocks are located in the relatively small area. They are concentrated near the Rachiv Massif and Chivchin Ridge, generally in the front of the Rahiv and Maramuresh (=Marmaros) nappes (Outer Flysch Carpathians) and in the Pieniny Klippen Belt. Several outcrops in these regions were studied in details by present authors. Rachiv nappe contains basaltic flows with numerous pillow lava horizons, ophicalcite(?) and with lava breccias on the top of volcanic sequence (Trostianets stream), as well as basaltic and tuffitic breccias (Lemskij stream). Maramuresh nappe contains andesites, basalts and tuffitic breccias often associated with light-grey micritic and coral limestones of Âtramberk-type facies (Kamennyj Potok stream). Most spectacular region of distribution of magmatic rocks belongs to Maramuresh unit and is located between Margetul, Radomir and Kwasnyj streams. These rocks are represented mainly by massive and pillow basalts, basaltic and tuffitic breccias and diabases as well as porphyritic conglomeratic/breccias. Usually they build huge klippes up to 50 meters and more. The contacts between huge pillow basaltic flows and surrounding deposits are usually covered by debris or vegetation but in Margetul stream the relationship between pillow lavas and pelagic, micritic limestones with cherts (Cieszyn Limestone Formation type) is very well visible. In the lower part of section small lenses of basaltic rocks occur within these limestones and basaltlimestone ratio increases upwards. Latest Jurassic - earliest Cretaceous age of these limestones was established helping to determine crucial age of a magmatic event to understand most important wide geodynamic processes. The basaltic rocks with pillow lavas are exposed in Veliky Kamenets quarry within Ukrainian part of the Pieniny Klippen Belt. These basalts cover the Middle Jurassic - lowermost Creataceous carbonate sequence, the contact is sharp and basaltic dykes also penetrate underlying Calpionella limestones. Above these basalts, there are younger limestones rich both in ammonites and benthic fauna (brachiopods, bivalves and crinoids) and they are overlain by 1 meters thick tuffites. The youngest deposits in the Veliky Kamenets section are yellowish limestone breccias showing presence of abundant Berriasian calpionellids. Sedimentological features of this breccia indicate submarine erosion connected with synsedimentary movements of the sea bottom causing redeposition of older rocks - in this case Calpionella limestones and basaltic fragments. These sediments correspond very well with Walentowa Breccia Member of the Dursztyn Limestone Formation which originated after strong Neo-Cimmerian uplift of the Czorsztyn Ridge. Additionally, in Vulhovchik stream, just below Veliky Kamenets hill, Jurassic/Cretaceous trachydolerites occur. These magmatic events correspond very well with major plate reorganization, which happened during the Tithonian time within western Tethyan Ocean. In the same time the Outer Carpathian rifts were developed with the extensional type of volcanism (teschenites) and the Silesian Basin originated as a result of such rifting process. The presumable triple-junction zone comprises the Rahiv-Sinaia zone (first arm), Silesian (second one) and its extension into the Pieniny Klippen Belt/Magura Basin (third arm). The origin of this triple junction is perhaps related to the opening of the Central Atlantic-Ligurian-Penninic oceanic system.

Słowa kluczowe

EN

Carpathians; Jurassic/Cretaceous; Ukraine; volcanism

• Wydawca: Państwowy Instytut Geologiczny - Państwowy Instytut Badawczy
• Czasopismo: Volumina Jurassica
• Rocznik: 2006
• Tom: Vol. 4, no. 1
• Strony: 52--53

Twórcy

autor

Krobicki M.

autor

Golonka J.

autor

Malata E.

autor

Oszczypko N.

autor

Słaby E.

autor

Słomka T.

• Faculty of Geology, Geophysics and Environmental Protection, AGH University of Science and Technology, Mickiewicza 30, PL-30059 Kraków, Poland,