Estratigrafía del Grupo Baqueró, Patagonia (provincia de Santa Cruz, Argentina)

TLDR: In this article, the Baquero Croup is considered at a higher rank, Baqueros Croup, that includes, from bottom to top the fol1owing forrnations: Anfiteatro de Tico, Bajo Tigre, and Punta del Barco.

Abstract: The stratigraphy of early Cretaceous strata in the central area of Santa Cruz Province has been a matter of study since the time when E.W. Berry published his first paleobotanical descriptions in 1924. Detailed sedimentological a nd petrographica 1investiga tions performed d uring recent years in the area of Meseta Baquero, Bajo Tigre and Anfiteatro de Tico localities have been added to the available paleontological information. It is now possible to present a new strabgraphic interpretabon of the sequence that has been previously referred to the Baquero Forrnation. This unit is now considered at a higher rank, Baquero Croup, that includes, from bottom to top the fol1owing forrnations: Anfiteatro de Tico, Bajo Tigre and Punta del Barco. The stratotypes for each unit are located and the main lithofacies are described and interpreted. Fossil plant assemblages are placed in this new stratigraphic context and related to paleoenvironments that were strongly influenced by recurrent volcanic ash fal\. A model of paleoenvironmental development and changing geographic sceneries is also discussed. On the basis of paleobotanical and palynological data, a Barremian to Aptian age was previously suggested for the Baquero Group. Recent isotopic datings confirm an Aptian age.