Scleractinian corals from lower cretaceous deposits north of Esfahan (central Iran)

Abstract

A new section through Cretaceous deposits was discovered 1 km west of the Dizlu village (approximately 40 km north of Esfahan, central Iran). Lithologically, the section distinctly differs from all other sections exposed in neighboring localities. A scleractinian coral fauna (Upper Aptian-Upper Albian), collected from a reefal limestone, is described in detail. The following taxa were found:Actinastrea aff.pseudominima (Koby),Columactinastraea sp.,Eugyra cotteaui (d'Orbigny),Pseudomyriophyllia turnsekae Baron-Szabo,Montlivaltia sp.,Paraclausastrea pulchra Morycowa,Placocoenia robusta Oppenheim,Columnocoenia ksiazkiewiczi Morycowa,Stylina micropora Koby,Felixigyra deangelisi Prever,Cyathophora haysensis Wells,Diploastraea harrisi Wells,Morphastrea cf.ludovicina (Michelin),Meandrophyllia meandroides (Koby),Eocomoseris raueni Loser,Fungiastrea crespoi (Felix),Latiastraea cf.kaufmanni (Koby),Kobya aff.crassolamellosa Gregory. The coral association of the Esfahan region is dominated by forms that are known to be cosmopolitan and semicosmopolitan in the Lower Cretaceous. It was found that over 40% of the coral fauna had previously been reported from both Lower and Upper Cretaceous strata. A similar pattern has been recognized for other reefal associations (e.g. Albian of Greece and Upper Barremian-Middle Albian of Mexico). In contrast, coral assemblages which developed in rather soft bottom environments have a significantly smaller percentage (15–20%) of taxa extending into the Upper Cretaceous and show closer affinities to Upper Jurassic and Lower Cretaceous faunas.