Naslov
Medvednica and Kalnik Mountains – remnants of the Meliata-Hallstatt Ocean in the western Pannonian Basin?

Autori
Goričan, Špela ; Halamić, Josip

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Izvornik
Interrad VIII / - Pariz, 1997

Skup
Interrad

Mjesto i datum
Pariz, Francuska, 08.09.1997. - 13.09.1997

Vrsta sudjelovanja
Predavanje

Vrsta recenzije
Nije recenziran

Ključne riječi
radiolarite; Triassic; Jurassic; Medvednica Mt.; Kalnik Mt.; northern Croatia; Meliata-Hallstatt ocean

Sažetak
An incoplete ophiolite sequence comprising gabbro, basalt and bedded radiolaria chert is exposed in the Medvednica and Kalnik Mountains in northern Croatia. Bedded cherts directly overlying pillow lavas in two sections on the Kalnik Mt. yielded Middle Carnian and latest Carnian-Norian radiolarians respectively. Late Ladinian and Carnian radiolarians were found in bedded chert on the Medvednica Mt. but the base of this chert is not known due to tectonic disruption. Triassic radiolarites from the study area have been described by Halamić & Goričan (1995). The Jurassic part of the succession consists of radiolarian chert and matriks-supported polymict conglomerates with centimeter- to decimeter-size clasts of greywacke, siltstone, chert, and basalt. Larger limestone olistoliths occur locally. Bathonian to early Callovian radiolarians were found in the associated chert beds at 14 localities on the Medvednica Mt. Sea-floor spreading in the study area occurred from Middle Carnian or possibly Late Ladinian to the latest Carnian-Norian. Bathonian-Callovian polymict conglomerates were probably related to subduction. The best correlation with the succession studied is with the Meliata Unit in Hungary and slovakia where Ladinian to Lower Carnian pillow basalts and radiolarian cherts are overlain by Jurassic turbidites and olistostromes (Kozur, 1991). It should, nevertheless, be noted that sea-floor spreading in the study area was still active in Late Carnian times whilst activity had most probably already ceased in the Meliata Basin. Carnian-Norian radiolarian cherts directly overlying pillow lavas of MORB-type are also known from the Vardar Zone in Serbia (locality Čačak in Obradović & Goričan, 1988 and Robertson & Karamata, 1994).

Izvorni jezik
Engleski

Znanstvena područja
Geologija

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