Paleobathymetry and paleoecology of colonial corals from the Oligocene–early Miocene (?) Qom Formation (Dizlu area, central Iran)

• Published in: Carbonates and evaporites Vol. 27; no. 3-4; pp. 395 - 405
• Main Authors: Yazdi, Mehdi, Shirazi, Mahnaz Parvanenejad, Rahiminejad, Amir Hossein, Motavalipoor, Razieh
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer-Verlag 01.12.2012; Springer Nature B.V
• Subjects: Carbonates; Colonies; Corals; Depth; Earth and Environmental Science; Earth Sciences; Faviidae; Flooding; Geology; Identification; Intervals; Leptoseris; Light intensity; Luminous intensity; Madracis; Marine invertebrates; Mineral Resources; Mineralogy; Miocene; Oligocene; Original Article; Palaeoecology; Paleoecology; Poritidae; Sedimentary facies; Siderastreidae; Species; Stylophora; Water depth; Iran; Paleobathymetry; Coral; Qom Formation; Colonial growth morphology; Central Iran; Paleoecology; Oligocene–early Miocene (?)
• ISSN: 0891-2556; 1878-5212
• DOI: 10.1007/s13146-012-0122-5

The scleractinian corals from the carbonate facies of the Oligocene–early Miocene (?) Qom Formation in Dizlu area (northern Isfahan), central Iran were described in three separate coral intervals. From the base to the top of the study carbonate sequence, the coral assemblages of the intervals include 1— Madracis , 2— Leptoseris – Stylophora and 3—Poritidae–Faviidae–Siderastreidae. The species identified within the carbonates are dominated by: Goniopora sp., Pachyseris sp., Madracis cf. ornate , Madracis sp., Montastraea parva , Solenastrea cf. desmoulinsi , Tarbellastraea reussiana , Stylophora sp., Siderastrea crenulata and Leptoseris sp. The identified colonial coral species were not colonizing through a strong carbonate reefal structure. Instead, they were distributed as sparse patches or building coral biostromal frameworks. The thin branching colonies of Madracis species and the second coral assemblage ( Leptoseris – Stylophora ) that is dominated by thin branching and thin platy colonial growth forms reflect deeper depths of a carbonate ramp with low light intensity within the lower photic zone in a depth range of 19–35 m and a maximum flooding surface. The coral associations of the Poritidae–Faviidae–Siderastreidae assemblage are mainly composed of massive colonies indicating the upper photic zone with depth of less than 20 m and a higher energy water regime. The three coral assemblages reflect marine paleotemperature of 19–20° C, respectively.