A new lithographic limestone deposit in the Upper Cretaceous Austin Group at El Rosario, county of Múzquiz, Coahuila, northeastern Mexico

  • Wolfgang Stinnesbeck Universität Karlsruhe, Geologisches Institut, Postfach 6980, D-76128 Karlsruhe, Germany.
  • Christina Ifrim Universität Karlsruhe, Geologisches Institut, Postfach 6980, D-76128 Karlsruhe, Germany.
  • Harald Schmidt Universität Karlsruhe, Geologisches Institut, Postfach 6980, D-76128 Karlsruhe, Germany.
  • Anja Rindfleisch Universität Karlsruhe, Geologisches Institut, Postfach 6980, D-76128 Karlsruhe, Germany.
  • Marie Céline Buchy Universität Karlsruhe, Geologisches Institut, Postfach 6980, D-76128 Karlsruhe, Germany.
  • Eberhard Frey Geowissenschaftliche Abteilung, Staatliches Museum für Naturkunde, Erbprinzenstrasse 13, D-76133 Karlsruhe, Germany.
  • Arturo H. González-González Museo del Desierto, Prolongación Pérez Treviño 3745, Centro Metropolitano Parque Las Maravillas, 25015 Saltillo, Coahuila, Mexico.
  • Francisco J. Vega Instituto de Geología, Universidad Nacional Autónoma de México, Coyoacán, 04510 México, D.F., Mexico
  • Lionel Cavin Department of Palaeontology, The Natural History Museum, Cromwell Road, London SW7 5BD, UK.
  • Gerta Keller Department of Geosciences, Princeton University, Guyot Hall, Washington Rd., Princeton, NJ 08544-1003, USA.
  • Krister T. Smith Department of Geology and Geophysics, Yale University, P.O.Box 208109, New Haven, CT 06521-8109, USA.
Keywords: Upper Cretaceous, fossil preservation, Konservat-Lagerstätte, limestone, Coahuila, Mexico.

Abstract

At El Rosario, 170 km WNW of Múzquiz in northern Coahuila, Mexico, alternating evenly layered platy limestone and fissile marly limestone of late Turonian-early Coniacian age (Late Cretaceous) contain vertebrate fossils with exceptionally well-preserved anatomical details of their soft tissues, as well as abundant ammonoids, inoceramids and other invertebrates. Deposition was in an open marine shelf environment near the southern opening of the Western Interior Seaway, several hundreds of kilometers south of the North American coastline, in water depths of at least 50–100 m. The present research intends to highlight the enormous preservational potential of this new conservation deposit (Konservat- Lagerstätte) and to analyze the paleoenvironmental conditions present at this locality. Our preliminary data suggest that the El Rosario fossil deposit is a combined result of anoxic bottom conditions, early diagenetic phosphatization, and rapid burial in a soft, micritic lime mud.

Published
2018-04-24
Section
Articles