Lower Tithonian ammonites from the Chaman Bid Formation in northeastern Iran, Koppeh-Dagh Basin
نویسندگان
1 Research Institute for Earth Sciences, Geological Survey of Iran
2 GeoZentrum Nordbayern, Friedrich-August Universität Erlangen-Nürnberg
3 Freie Universität Berlin, Institut für Geologische Wissenschaften
4 School of Mining Engineering, University College of Engineering, University of Tehran
doi
10.22059/geope.2017.212475.648265چکیده
The type section of the Middle and Upper Jurassic Chaman Bid Formation is in the western Koppeh Dagh Basin (Northeast Iran). It is unusually thick and contains a rather rich ammonite fauna, ranging from Bathonian to Tithonian. The ammonites described here come from a 134-m-thick interval in the upper part of member (D) in the middle part of the formation, consisting of an alternation of grey limestone and marly limestone. The following ammonite families are present: Haploceratidae, Oppeliidae, Perisphinctidae, and Ataxioceratidae, among them the following taxa have being recorded for the first time from Iran: Phanerostephanus subsenex, Phanerostephanus aff. intermedius, Nothostephanus aff. kurdistanensis, Nannostephanus cf. subcomutus and Oxylenticeras cf. lepidum. This assemblage is belonging to the Lower Tithonian Semiforme Zone or even older zones. The Fallauxi Zone is represented by Richteria richteri.
