Paleontology and sedimentology of Middle Eocene rocks in Lago Argentino area, Santa Cruz Province, Argentina

Authors

  • Silvio Casadío
  • Miguel Griffin
  • Sergio Marenssi
  • Laura Net
  • Ana Parras
  • Martín Rodriguez Raising
  • Sergio Santillana

Abstract

Sedimentological and paleontological study of the Man Aike Formation at the Estancia 25 de Mayo, SW of Santa Cruz Province, Argentina, represents the evolution of an incised valley from fluvial to marine environment during the late middle Eocene. At the base of the unit there is an unconformity that corresponds to fluvial channels which cut down into the underlying Maastrichtian sandstones of the Calafate Formation. The fauna of invertebrates (mostly molluscs) illustrated herein was collected from shell beds interpreted as tidal ravinement surfaces. The fauna includes terebratulid brachiopods, bivalves of the families Malletiidae, Mytilidae, Pinnidae, Ostreidae, Pectinidae, Carditidae, Crassatellidae, Lahillidae, Mactridae, Veneridae, and Hiatellidae, and gastropods of the families Trochidae and Calyptraeidae, and a member of Archaeogastropoda of uncertain affinities. The similarities of this fauna with that recorded in the Upper Member of the Río Turbio Formation, together with 87Sr/86Sr ages, suggest a late Middle Eocene age for the Man Aike Formation.

How to Cite

Casadío, S., Griffin, M., Marenssi, S., Net, L., Parras, A., Rodriguez Raising, M., & Santillana, S. (2009). Paleontology and sedimentology of Middle Eocene rocks in Lago Argentino area, Santa Cruz Province, Argentina. Ameghiniana, 46(1), 27-48. Retrieved from https://ameghiniana.org.ar/index.php/ameghiniana/article/view/175

Issue

Section

Articles

Most read articles by the same author(s)

1 2 3 4 > >>