Contribution
Ophiolites and Related Formations in the Central Part of the Sabzevar Range (Iran) and Possible Geotectonic Reconstructions
Baroz, F.; Macaudière, J.; Montigny, R.; Noghreyan, M.; Ohnenstetter, M.; Rocci, G.
Neues Jahrbuch für Geologie und Paläontologie - Abhandlungen Band 168 Heft 2-3 (1984), p. 358 - 388
66 références bibliographiques
publié: Jun 28, 1984
publication en ligne: Jul 27, 2018
DOI: 10.1127/njgpa/168/1984/358
ArtNo. ESP155016802015, Prix: 29.00 €
Abstract
In the central part of the Sabzevar range, NE Iran, structural and petrological studies have been undertaken on ophiolites, Upper Cretaceous volcano-sedimentary sequences and metamorphic rocks of the Soltanabad area. During ophiolite formation, several intrusions have been recognized considering dyke relationships and crystallization order in cumulates. Internal consistencies, dating of magmatic amphiboles (Coniacian) and paleomagnetic data are in favour of the genesis of ophiolites in limited extensional areas. These ophiolites are overlain by an Upper Cretaceous to Paleocene volcano-sedimentary sequence developed from juxtaposed ridges and troughs filled with island arc calc-alkalic and alkalic volcanics and sediments. The metamorphic rocks from the Soltanabad area are of intermediate type between greenschist and blueschist facies. The basic metamorphic rocks may belong to pre-ophiolitic transitional to alkalic series, whereas epidote gneisses, dioritic to tonalitic in composition, are similar to the ophiolitic suite. The culmination of metamorphism occurred during pre-Lutetian tectonic phases which led to the building of the Sabzevar range. A model for the structural evolution of the belt is proposed. It emphasizes the role of a strike-slip system during the opening of the ocean and the major part of its closure, the latter events being more purely but not exclusively compressive.
Mots-clefs
Ophiolite • volcano-sedimentary sequence • Upper Cretaceous • metamorphic rock • petrographical feature • tectonic feature • geochronology • geochemistry • chemical analysis • structural evolution • Iran