Turonian ammonite faunas from the southern Corbières, Aude, France

Abstract

Abstract The Turonian successions of the southern Corbieres comprise three transgressive-regressive cycles in which ammonites occur in three intervals. The lowest comes from the glauconitic basal transgressive unit of the first cycle, and comprises 21 species, including Kamerunoceras douvillei (Pervinquiere, 1907), Kamerunoceras turoniense (d’Orbigny, 1850), Spathites (Jeanrogericeras) revelerianus (Courtiller, 1860), Spathites (Jeanrogericeras) combesi (d’Orbigny, 1856), Mammites nodosoides (Schluter, 1871), Mammites powelli Kennedy, Wright and Hancock, 1987, Fagesia tevestensis (Peron, 1896), Neoptychites cephalotus (Coutiller, 1860), Thomasites rollandi (Thomas and Peron, 1889), Wrightoceras wallsi Reyment, 1954, and Choffaticeras (Choffaticeras) quaasi (Peron, 1904). This is a Lower Turonian assemblage referred to the Mammites nodosoides Zone, although the possibility that elements from the preceding Fagesia catinus Zone are also present cannot be excluded. The fauna from the transgressive glauconitic interval of the succeeding cycle comprises nine species, including Romaniceras (Romaniceras) mexicanum Jones, 1938, Romaniceras (Yubariceras) ornatissimum (Stoliczka, 1864), Pseudotissotia galliennei (d’Orbigny, 1850), Collignoniceras woollgari (Mantell, 1822) sensu lato, Coilopoceras springeri Hyatt, 1903, and Eubostrychoceras (Eubostrychoceras) saxonicum (Schluter, 1872). They indicate the Middle Turonian Romaniceras (R.) mexicanum and R. (Y.) ornatissimum zones. The highest fauna, from the Marnes superieurs de Saint-Louis of the Saint-Louis syncline, is: Subprionocyclus sp. juv., Prionocyclus sp. and Worthoceras cf. rochatianum (d’Orbigny, 1850). The Subprionocyclus are minute individuals that resemble S. bravaisianus (d’Orbigny, 1841), and suggest the presence of the lower Upper Turonian bravaisianus Zone.