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The Eastern Carpathians „ophiolites” (Romania): Remnants of a Triassic ocean

Domenii publicaţii > Ştiinţele pământului şi planetare + Tipuri publicaţii > Articol în revistã ştiinţificã

Autori: Hoeck, V., Ionescu, C., Balintoni, I., Koller, F.

Editorial: A.H.F. Robertson, S. Karamata and K. Šarić, Elsevier Science B.V., Lithos, 108, p.151-171, 2009.

Rezumat:

Mesozoic ophiolitic and related rocks in the Eastern Carpathians occur in three areas, from north to south:
Rarau, Haghimas and Persani Mts. They are found as blocks ranging from few metres to a few kilometers in
size and as centimetre-sized in breccias, most likely embedded in the Late Barremian–Early Albian Wildflysch
formation. Compositionally, they range from lherzolites and harzburgites to mafics such as FeTi gabbros,
dolerites, basalts, and to andesites. The volcanics comprise highly-depleted basalts/andesites to enrichedtype
mid-ocean ridge basalts; additionally they include ocean island basalts and calc-alkaline basalts/
andesites and trachytes. Based on paleontological evidence, their age is Middle to ?Late Triassic. They can be
clearly compared with remnants of the Meliata–Hallstatt Ocean in the Western Carpathians, but do not
match the Jurassic ophiolites and island arc volcanics in the Mures Zone of the Southern Apuseni Mts. We
propose a Triassic ocean connected with the Meliata–Hallstatt Ocean, between (a) the Bucovinian/Sub-
Bucovinian continental crust, (b) the Infrabucovinian and finally (c) the Northern Apuseni microcontinents.
This ocean closed in the Late Triassic to Early Jurassic causing close juxtaposition of all three microcontinents.
An ophiolite complex together with ocean island basalts and calc-alkaline basalts/andesites remained from
this ocean and was subsequently eroded and transported as blocks of different size into the Lower Cretaceous
Wildflysch basin, together with blocks and clasts of limestones similar to the Mesozoic sedimentary
sequences in the Northern Apuseni realm. The Wildflysch formation was thrust as an independent unit
during the Albian over the Bucovinian Nappe in the Eastern Carpathians and the Northern Apuseni
continental crust, respectively.

Cuvinte cheie: Carpatii Orientali, Apusenii de Sud, ofiolite, Triasic, Jurasic, Oceanul Meliata-Hallstatt, Oceanul Vardar // Eastern Carpathians, Southern Apuseni Mountains, ophiolite, Triassic, Jurassic, Meliata-Hallstatt Ocean, Vardar Ocean

URL: http://www.sciencedirect.com/science?_ob=PublicationURL&_cdi=5816&_pubType=J&_auth=y&_acct=C000050221&_version=1&_urlVersion=0&_userid=10&md5=310047a175fca2e60541db2e5065fc07&jchunk=108#108