BOLETÍN DE LA SOCIEDAD GEOLÓGICA MEXICANA Volumen 66, núm. 1, 2014, p. 11-23 http://dx.doi.org/10.18268/BSGM2014v66n1a2

Reporte preliminar sobre la paleoflora de la Formación La Colonia (Campaniano-Maastrichtiano, Cretácico tardío), Chubut, Patagonia, Argentina

María A. Gandolfo^1,*, N. Ruben Cúneo², Elizabeth J. Hermsen³

¹ L-H Bailey Hortorium, Department of Plant Biology, 412 Mann Library Building, Cornell University, Ithaca, NY, 14853, EUA.
² MEF-CONICET, Av. Fontana 140, Trelew, 9100, Chubut, Argentina.
³ Departament of Environmental and Plant Biology, Porter Hall 401, Ohio University, Athens, OH, 45701, EUA.

^* This email address is being protected from spambots. You need JavaScript enabled to view it.

Abstract

In this contribution, we present new paleofloristic elements from the La Colonia Formation (Campanian-Maastrichtian, Late Cretaceous), exposed between Telsen and Sierra Rosada in the area known as the North Patagonian Massif, Chubut, Patagonia, Argentina. Previously, the paleoflora was only known from some of its aquatic components: pteridophytes representing the families Salviniaceae and Marsileaceae and angiosperms representing the families Nelumbonaceae. However, recent paleobotanical collections have revealed the presence of a more diverse plant assemblage including other aquatic elements as well as terrestrial ferns, conifers, and several angiosperms. Among the aquatics, macrofossils similar to Azolla (pteridophyte), and two angiosperms related to the families Araceae and Typhaceae are described; while the terrestial components are represented by fossils of Dicksonianceae (pteridophyten), a putative araucariacean conifer, and six dicot morphotypes. The aquatic elements are intepreted as autochtonous and the terrestial as allochtonous. The taphocenosis confirms the environmental interpretation previously suggested for the middle sector of the La Colonia Formation.

Keywords: Argentina, Late Cretaceous, La Colonia Formation, paleoecology, paleoflora.