Latest Oxfordian – earliest Kimmeridgian ammonite dominated fauna and microfacies from the ammonitico rosso-type Fonyászó Limestone Formation at Zengővárkony (Mecsek Mountains, Hungary)

Abstract

Field work has resulted in the recognition of a previously unknown outcrop in the vicinity of the Zengővárkony lime-kilns (Mecsek Mountains, South Hungary) which has provided a remarkably rich, but poorly preserved, uppermost Oxfordian – earliest Kimmeridgian fauna dominated by ammonites probably representing the Hypselum–Bimammatum zones. This is the first description and illustration of Oxfordian–Kimmeridgian ammonites from the Mecsek Mountains. The cephalopod fauna comprises Phylloceras div. sp., Holcophylloceras div. sp., Sowerbyceras sp., Lytoceras sp., Lissoceratoides erato, Trimarginites cf. trimarginatus, Glochiceras (Coryceras) cf. microdomum, Subdiscosphinctes sp., ?Wegelea sp., Passendorferiinae gen. et sp. ind., ?Orthosphinctes sp., Euaspidoceras cf. radisense, Aspidoceras sp., A. cf. binodum, Physodoceras sp. ex gr. altenense-wolfi, Lamellaptychus sp., Laevaptychus sp. ex gr. hoplisus-obliquus. The fauna has a Mediterranean character (55% of Phylloceratidae and Lytoceratidae) and is similar to the Tethyan assemblages of the Venetian Alps (Italy), and Palma de Mallorca. The spirochaete tube worm Spiraserpula spirolinites is also the first record from the Mecsek Mountains. The Saccocoma wackestone-packstone microfacies is recorded with benthic foraminifera (Lenticulina sp. and Spirillina sp.) indicating well oxygenated and nutrient-rich bottom conditions.