Amazonian magnetostratigraphy: Dating the first pulse of the Great American Faunal Interchange |
| |
| Authors: | Kenneth E Campbell Donald R Prothero Lidia Romero-Pittman Fritz Hertel Nadia Rivera |
| |
| Institution: | 1. Florida Museum of Natural History, University of Florida, Gainesville, FL, 32611, USA;2. Department of Earth and Environmental Sciences, Lehigh University, Bethlehem, PA 18015, USA;3. Department of Earth Sciences, University of California Santa Barbara, Santa Barbara, CA 93106, USA;4. Facultad de Ingeniería Geológica, Universidad Autónoma Tómas Frías, Potosí, Bolivia;1. Institut des Sciences de l’Evolution, UMR 5554 CNRS, IRD, EPHE, Université de Montpellier, Place Eugène Bataillon, 34095 Montpellier cedex 5, France;2. Laboratorio de Sistemática y Biología Evolutiva (LASBE), Museo de la Plata, Paseo del Bosque s/n, B1900FWA La Plata, Argentina;3. Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Argentina;4. Museo de Historia Natural-Universidad Nacional Mayor San Marcos, Departamento de Paleontología de Vertebrados, Avenida Arenales 1256, Lima 11, Perú;5. Géosciences-Environnement Toulouse, Université de Toulouse, UPS (SVT-OMP), LMTG, CNRS, IRD, 14 Avenue Édouard Belin, F-31400 Toulouse, France;6. Convenio IRD-PeruPetro, Av. Luis Aldana 320, San Borja, Lima, Peru;7. Sorbonne Universités, CR2P, MNHN, CNRS, UPMC-Paris 6, Muséum national d''Histoire naturelle, CP 38, 8 rue Buffon, 75231 Paris cedex 05, France;8. División Paleontología Vertebrados, Museo de la Plata, Paseo del Bosque s/n, B1900FWA La Plata, Argentina;9. Department of Geosciences, University of Oslo, P.O. Box 1047 Blindern, NO-0316 Oslo, Norway;10. Department of Anatomy, School of Medicine, Case Western Reserve University, Cleveland, OH 44106, USA;11. Geological Survey of Norway, 7491 Trondheim, Norway;12. Center for Tropical Paleoecology and Archeology, Smithsonian Tropical Research Institute, Balboa, Ancon AA 0843-03092, Panama;13. Department of Ecology and Evolution, J.W. Goethe University, Max-von-Laue-Str. 13, 60438 Frankfurt a. M., Germany;14. Paleosedes E.U. Tv 27 n°57-49 Campin, Bogotá, Colombia;15. CONICET, Museo Paleontológico Egidio Feruglio, Av. Fontana 140, Trelew, Argentina;p. Field Museum of Natural History, 1400 Lake Shore Drive, Chicago, IL, USA;q. IANIGLA, CCT–CONICET–Mendoza, Avenida Ruiz Leal s/n, Parque General San Martín, 5500 Mendoza, Argentina;r. Department of Earth and Environmental Sciences, Lamont Doherty Earth Observatory of Columbia University, Palisades, NY 10964, USA;s. Division of Vertebrate Paleontology, American Museum of Natural History, NY 10024, USA;t. Department of Mammalogy, Natural History Museum of Los Angeles County, Los Angeles, CA, USA;u. Department of Paleobiology, National Museum of Natural History, Smithsonian Institution, Washington, DC, USA;v. Naturalis Biodiversity Center, P.O. Box 9517, 2300 RA Leiden, Netherlands |
| |
| Abstract: | The chronostratigraphy of the youngest Neogene deposits of the Amazon Basin, which comprise the Madre de Dios Formation in eastern Peru, remains unresolved. Although 40Ar/39Ar dates on two volcanic ashes from this formation in Peru provide critical baseline data points, stratigraphic correlations among scattered riverine outcrops in adjacent drainage basins remain problematic. To refine the chronostratigraphy of the Madre de Dios Formation, we report here the magnetostratigraphy of an outcrop on the Madre de Dios River in southeastern Peru. A total of 18 polarity zones was obtained in the ～65-m-thick Cerro Colorado section, which we correlate to magnetozones Chrons C4Ar to C2An (9.5–3.0 Ma) based on the prior 40Ar/39Ar dates. These results confirm the late Miocene age of a gomphothere recovered from the Ipururo Formation, which underlies the late Miocene Ucayali Unconformity at the base of the Cerro Colorado outcrop. The results also support earlier interpretations of a late Miocene age for other fossils of North American mammals recovered from basal conglomeratic deposits of the Madre de Dios Formation immediately above the Ucayali Unconformity. These mammals include other gomphotheres, peccaries, and tapirs, and their presence in South America in the late Miocene is recognized as part of the first pulse of the Great American Faunal Interchange. |
| |
| Keywords: | |
| 本文献已被 ScienceDirect 等数据库收录！ |
|
