Revista del Museo Argentino de Ciencias Naturales
versión On-line ISSN 1853-0400
HOLLIS, Chris; ARCHANGELSKY, Sergio y CARDENAS, Orlando. Early Cretaceous Radiolarians from southernmost Patagonia, Argentina. Rev. Mus. Argent. Cienc. Nat. [online]. 2009, vol.11, n.1, pp. 33-37. ISSN 1853-0400.
A radiolarian assemblage found in the lowermost strata of the Río Mayer Formation, as exposed at Estancia La Federica in Santa Cruz Province, Argentina, is described. The biostratigraphic markers of this assemblage indicate a late Berriasian-early Barremian age (early Early Cretaceous). The radiolarians have faunal affinities with early Cretaceous assemblages reported from offshore northwestern Australia and the western Pacific, northeast of New Zealand. A cool-water affinity is suggested for the Patagonian assemblage. Ten meters below the levels with radiolarians sediments bearing continental palynomorphs are found. They are referred to the Springhill Formation of Berriasian to Valanginian age.
Palabras llave : Radiolarians; Rio Mayer Formation; Late Berriasian-early Barremian; Santa Cruz; Argentina.