Quick Search:    advanced search

GSW Home   GeoRef Home   My GSW Alerts   Contact GSW   About GSW   Journals List   Help

This Article Résumé Full Text (PDF) Submit a response Alert me when this article is cited Alert me when eLetters are posted Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in Web of Science Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Web of Science (2) Citing Articles via Google Scholar Google Scholar Articles by Babazadeh, S. A. Articles by De Wever, P. Search for Related Content GeoRef GeoRef Citation

Radiolarian Cretaceous age of Soulabest radiolarites in ophiolite suite of eastern Iran

¹ Faculty of Sciences, Payame noor university of Birjand, Birjand, Iran ; Current address : ISTO, Université d’Orléans, Bâtiment Géosciences, Rue St. Amand, BP 6759, 45067, Orléans, France
² Laboratoire de Géologie, Muséum National d’Histoire Naturelle, 43 Rue Buffon, F-75005 Paris, France

Abstract

The ophiolite-flysch range (accretionary prism) of the Sistan suture zone from eastern Iran includes several intensely deformed tectonic units, some of which consist of volcaniclastic rocks, volcanic rocks, siliceous pelagic sediments (cherts and radiolarites) and calcareous rocks (deep marine, platform), whereas others are represented by terrigenous turbidites. The Soulabest radiolarites are located in the Ratuk complex of the Tirrul’s subdivision [Tirrul et al. , 1983], or in the ophiolite suite of the Gazik province.

The local biostratigraphy of this region is based on two faunal assemblages. Faunal assemblage I is dated early Aptian, faunal assemblage II is attributed to middle-late Albian. The most abundant fauna is found in the middle-late Albian. The timing of the oceanic opening in eastern Iran remained questionable until now. The study of the radiolarites of the Soulabest area provides new data for dating the primary opening between two microcontinents : the Lut and Afghan blocks. It is proposed that the oceanic opening of the two blocks occurred prior to the early Aptian. In previous reports, the age of opening was attributed to Upper Cretaceous.

All reported Radiolaria are found in red radiolarites and green-red argillaceous cherts. This formation is unconformably overlain by Maastrichtian conglomerates. It indicates that the closure of the basin occurred in Maastrichtian age.

Key Words: Eastern Iran • Lut and Afghan blocks • Sistan suture zone • Gazik Province • Ophiolite Suite • Soulabest Radiolarites • Cretaceous Radiolaria