Ammonoids, their biozonation and their palaeobiogeographic relation across the Turonian-Coniacian boundary in northern Coahuila, Mexico

• Verfasst von: Ifrim, Christina [VerfasserIn]
• Verfasst von: Porras Múzquiz, Héctor [VerfasserIn]
• Verfasst von: Stinnesbeck, Wolfgang [VerfasserIn]
• Titel: Ammonoids, their biozonation and their palaeobiogeographic relation across the Turonian-Coniacian boundary in northern Coahuila, Mexico
• Verf.angabe: Christina Ifrim, Hector Porras Múzquiz, Wolfgang Stinnesbeck
• E-Jahr: 2019
• Jahr: 21 March 2019
• Umfang: 16 S.
• Fussnoten: Gesehen am 22.10.2019
• Titel Quelle: Enthalten in: Cretaceous research
• Ort Quelle: London : Academic Press, 1980
• Jahr Quelle: 2019
• Band/Heft Quelle: 102(2019), Seite 170-195
• ISSN Quelle: 0195-6671
• DOI: doi:10.1016/j.cretres.2019.03.014
• Datenträger: Online-Ressource
• Sprache: eng
• Sach-SW: Ammonoids
• Sach-SW: Biostratigraphy
• Sach-SW: Turonian-Coniacian boundary
• Sach-SW: Upper Cretaceous
• K10plus-PPN: 1679320882

Abstract

The Rosario section in northern Coahuila, northeastern Mexico, contains a complete record of distal shelf deposits across the Turonian-Coniacian boundary. Here we describe the ammonoids, the biozonation based on these cephalopods, their taphonomy and some palaeobiogeographic relations. Gaudryceras mite, Peroniceras (P.) tridorsatum, P. (P.) dravidicum, Forresteria (F.) alluaudi, F. (F.) brancoi, F. (F.) peruana, Baculites sweetgrassensis, B. yokoyamai, Neocrioceras maximum, Schlueterella stinnesbecki, Scaphites (S.) frontierensis, S. (S.) preventricosus, S. (S.) sagensis, and S. (S.) uintensis were identified at El Rosario and a nearby complementary outcrop at Carranza. The lower Coniacian Scaphites preventricosus, F. (F.) alluaudi, P. (P.) dravidicum and Neocrioceras maximum zones are represented and provide correlation with sections of the US Western Interior and Europe. The original index for the base of the Coniacian, F. (F.) peruana is also present, although few data exist below the Turonian-Coniacian boundary level. The ammonoids were not transported far before deposition, indicated by their preservation and size distribution. A moderate diversification in open-coiled diplomoceratids seemed to have started in the early Coniacian in this region. The El Rosario section provides a detailed ammonoid record and biozonation, and it is one of very few sections in the world where it can be correlated with the standard inoceramid biozonation.