Ammonites, inoceramids and stable carbon isotopes of the Cenomanian–Turonian OAE2 interval in central Europe: Pecínov quarry, Bohemian Cretaceous Basin (Czech Republic)

Abstract

In a well-exposed succession of Cenomanian through lower Turonian strata at Pecínov (Bohemian Cretaceous Basin, Czech Republic), a detailed study of ammonite and inoceramid assemblages was undertaken for the first time and combined with a revision of physical and carbon-isotope stratigraphy. The upper Cenomanian part of the OAE2 interval yielded a relatively rich ammonite assemblage containing Metoicoceras geslinianum (d'Orbigny, 1850), Calycoceras (Calycoceras) naviculare (Mantell, 1822), Pseudocalycoceras angolaense (Spath, 1931), Lotzeites aberrans (Kossmat, 1895), Euomphaloceras septemseriatum (Cragin, 1893), Sciponoceras gracile (Shumard, 1860), Allocrioceras annulatum (Shumard, 1860) and ?Puzosia sp. Inoceramid bivalves include Inoceramus pictus J. de C. Sowerby, 1829, Inoceramus sp. aff. Mytiloides praeturonicus Tröger, 2015 and Inoceramus cf. bohemicus Leonhard, 1897 in the Cenomanian part of the succession. The subspecies concept of the Inoceramus pictus group is modified here. The occurrence of Mytiloides puebloensis Walaszczyk and Cobban, 2000 indicates the lowermost Turonian Watinoceras devonense Zone. Earlier interpretation of the positive carbon-isotope excursion is refined here and a combined bio- and chemostratigraphic correlation is presented to successions from the Western Interior Seaway and the British Chalk.