Paleoambientes lacustres en la sección inferior de la Formación Río Negro, (Mioceno - Plioceno), Río Negro, Argentina
Keywords:
Paleoponds, Bivalve´s and Mammal foot prints, Río Negro FormationAbstract
This paper describes pond paleoenvironments from a marine platform sited in La Lobería, Río Negro Province, Argentina. Ponds are good indicators of paleoenvironmental evolution because they are very sensitive to changes in climatic conditions. The methodology used for this research consisted in dry
sieving, X-ray diffractometry analysis and paleontological observations. Three sections belonging to the lower section of the Río Negro formation were determined in the intertidal platform. The lower section is composed of fine-grained greenish gray sandstones deposited in an aeolian dune environment with acueos influence. The middle section consists of stratifield pinkish brown clayey to sandy fine silts with freshwater bivalve remnants and vertebrate footprints. The section is associated to restricted shallow ponds, extending to the NE. This level is overlaid by the upper section made of light bluish gray sandstones with cross to horizontal stratification, being deposited in an aeolian environment. At present the described ponds environment its affected by a strong marine erosion.
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Andreis, R.,1965. Petrografía y paleocorrientes de la Formación Río Negro, tramo Gral. Conesa - boca del Río Negro. Revista del Museo. La Plata. V Geología. 36: 20. 73
Angulo, R. y R. Casamiquela. 1982. Estudio estratigráfico de las unidades aflorantes en los acantilados de la costa norte del Golfo San Matías (Río Negro y extremo austral de Buenos Aires) entre los meridianos 62º 30 y 64º 30 W. Revista Mundo Ameghiniano. 2: 20 -73. Viedma.
Aramayo, S.; M. Barros; S. Candel ; L. Vecchi. 2004. Tetrapod footprints (Mammals and Bird) from Río Negro Formation (late Miocene -early Pliocene), Río Negro Province, Argentina. Resumen y Poster. Iº Congreso Internacional de Ichnología. ICHNIA (2004). Trelew. Argentina
Aramayo, S. 2007. Neogene vertebrate palaeoichnology of the north atlantic coast of the Rio Negro Province, Argentina. Arquivos do Museu Nacional. Río de Janeiro (en prensa).
Casamiquela, R. 1974. El bipedismo de los megateriodeos. Estudio de pisadas fósiles en la Formación Rio Negro típica. Ameghiniana. XI. 3
Collinson, J. D. 1978. Lakes: In Sedimentary Environments and Facies. H.D. Reading Ed. 61 - 71. Blavckwell Sc. Publ.
Diester - Haas, L; C Robert C.; H. Chamley. 1993. Palaeoceanographic and palaeoclimatic evolution in the Wedell Sea (Antarctica) during the middle Eocene late Oligocene, from a coarse sediment fraction and clay mineral data (OCP 689). Marine Geology 14. 233 - 250.
Rachold, V., H. I. Brumsack. 2001. Inorganic geochemistry of Albian sediments from the Lowen Saxonij Basin WW Germany: palaeoenvironmental constraints and orbital cycles. Palaeogeography, Palaeoclimatology, Palaeoecology, 174,121 – 123.
Kaukal, Z. 1971. Geology of recent sediments. Sc. Praga. Ed. Acad. Praga. 490.
Schillizzi, R., J. Spagnuolo; E. Gelós y S. Aliotta. 2005. Presencia y evolución de grandes bloques en la costa de Pta. Colorada, Golfo San Matías. GEOACTA 30. 30 - 45.
Wichmann, R. 1927. Sobre la facies lacustre senoniana de los Estratos con Dinosaurios y su fauna. Bol. Academia Nacional de Ciencias. Córdoba. T. 30. 383 - 405.
Zavala, C. and R. H. Freije. 2001. On the understanding of aeolian sequence stratigraphy: an example from Miocene - Pliocene deposits in Patagonia, Argentina. Revista Italiana di Paleontología e Stratigrafia. V. 107. 2: 251 - 264.
Zavala, C y H Freije. 2005. Geología de los acantilados. En Las mesetas patagónicas que caen al mar: La costa rionegrina. Ed. F. Masera. 187- 197. Río Negro.
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Copyright (c) 2008 Roberto Schillizzi, Liliana Luna
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