Biozonation and biostratigraphic limits of the Tarbur formation around Shiraz (SW of Iran)

Mehr als 3000m der karbonatischen Tarbur Formation wurden in der Umgebung der Stadt Schiras durch sieben stratigraphische Profile untersucht. Zur Alters bestimmung mittels Foraminiferen der Tarbur Formation wurden davon 900 Dünnschliffe bearbeitet. Die Biozonen dieser stratigraphischen Profile basieren auf den ermittelten Indexforaminiferen. An Hand der ermittelten typischen Biozonen wurde das Alter der Tarbur-Fomation dem Campan-Unterem Paläozän zugeordnet. Es wurden vier Hauptmikrofazies, die Wackstone, Packstone, Grainstone und Boundstone beinhalten, festgestellt. Auf Grund der untersuchten Biostratigraphie ist festzustellen, dass die Obergrenzen der Lithostratigraphie und der Biostratigraphie der Tarbur-Formation nicht übereinstimmen. Over 3000 meters of the Tarbur carbonate rocks Formation in seven stratigraphic sections have been studied. 900 thin sections have provided. The biozones have established and well known foraminifers are identified in these stratigraphic sections. Index Biozone reflects Campanian-Lower Paleocene age for the Tarbur Formation. Four index microfacies are distinguished which are, wackestone, Packstone, grainstone and boundstone. Based on biostratigraphic study, upper limit lithostratigraphic of the Tarbur Formation is not comparable with upper biostratigraphic boundary

Aptian biostratigraphy in South Zagros Basin, southwest Iran

The Khami group within the petroliferous Zagros Basin of Iran includes the Surmeh, Hith, Fahliyan, Gadvan and Dariyan formations. The Dariyan Formation, previously known as Orbitolina limestone is very significant as a reservoir rock in the Zagros Basin. In this study, the age of the Dariyan Formation is examined based on biostratigraphic and paleontological investigations. 236 m of Dariyan Formation sediments in the sections at Kuh-e Rahmat (north) and Nour-Abad (west) of Iran were selected to study its biostratigraphy. According to the lithostratigraphic investigations, the Dariyan Formation in these sections is subdivided into three: lower, middle and upper, which include thin-bedded to medium-bedded and massive limestone. Micropaleontologic study of the Dariyan Formation has led to the recognition of two biozones in the Nour-Abad area and one biozone in the Kuh-e Rahmat stratigraphic column. Diagnostic foraminifera in these sections are as follows: Globigerinelloides algerianus Cushman and Ten Dam, Globigerinelloides ferreolensis Moullade, Globigerinelloides maridalensis (Bolli), Globigerinelloides paragottisi Verga and Permoli Silva, Hedbergella aptiana Bartenstein, Hedbergella excelsa Longoria, Hedbergella luterbacheri Longoria, Hedbergella occulta Longoria, Hedbergella ruka (Banner et al.), Hedbergella similis Longoria, Hedbergella trocoidea (Gandolfi), Muricohedbergella delrioensis (Carsey), Pseudoplanomalina cheniourensis Sigal, Conicorbitolina conica d'Archiac, Iraqia sp., Mesorbitolina parva Douglass, Mesorbitolina pervia Douglass, Mesorbitolina ovalis Gorog and Arnaud-Vanneau, Mesorbitolina subconcava Leymerie, Mesorbitolina texana (Roemer), Mesorbitolina ovalis-pervia Cherchi and Schroeder, Debarina hahounerensis Fourcade et al., Marssonella trochus (d'Orbigny), Nezzazata sp., Orbitolina sp., Textularia sp. Based on the identified foraminifera, the age of the Dariyan Formation in the Kuh-e Rahmat area is assigned to Aptian, and in the Nour-Abad area is determined as upper Aptian