Early eocene 40Ar/39Ar age for the Pampa de Jones plant, frog, and insect biota (Huitrera Formation, Neuquén Province, Patagonia, Argentina)
The Pampa de Jones fossil site, a stratigraphically isolated roadcut near the northeastern shore of Nahuel Huapi Lake in Neuquén Province, Argentina, holds a rich fossil biota including a macroflora, a microflora, insects, and most famously, an ontogenetic series of pipid frogs. The site exposes tuf...
Guardado en:
| Autores principales: | , , , , |
|---|---|
| Formato: | JOUR |
| Materias: | |
| Acceso en línea: | http://hdl.handle.net/20.500.12110/paper_00027014_v47_n2_p207_Wilf |
| Aporte de: |
| id |
todo:paper_00027014_v47_n2_p207_Wilf |
|---|---|
| record_format |
dspace |
| spelling |
todo:paper_00027014_v47_n2_p207_Wilf2023-10-03T13:53:07Z Early eocene 40Ar/39Ar age for the Pampa de Jones plant, frog, and insect biota (Huitrera Formation, Neuquén Province, Patagonia, Argentina) Wilf, P. Singer, B.S. Zamaloa, M.D.C. Johnson, K.R. Rubén Cúneo, N. Argentina Early eocene Geochronology Huitrera formation Neuquén Paleobotany Patagonia age determination argon isotope biostratigraphy biotite climate variation Eocene fossil assemblage frog geochronology hypothesis testing insect mudstone ontogeny paleobotany Paleocene-Eocene boundary plant sandstone sanidine volcanism Argentina Nahuel Huapi Lake Anura Hexapoda Pipidae The Pampa de Jones fossil site, a stratigraphically isolated roadcut near the northeastern shore of Nahuel Huapi Lake in Neuquén Province, Argentina, holds a rich fossil biota including a macroflora, a microflora, insects, and most famously, an ontogenetic series of pipid frogs. The site exposes tuffaceous mudstone and sandstone beds of probable lacustrine origin, considered to belong to the volcanic Huitrera Formation. However, there have been no reliable age constraints for the fossil assemblage. We undertook laser fusion analyses of sanidine and biotite crystals occurring in a tuff layer found 4.4 m above the main fossil horizon. Twentyeight sanidine crystals yielded an 40ArZ39Ar age of 54.24 ± 0.45 Ma that is preferred over our biotite age of 53.64 ± 0.35 Ma. Pampa de Jones is thus the oldest well-dated Eocene fossil site in Patagonia, predating two other recently 40Ar/39Ar-dated sites: Laguna del Hunco (51.91 ± 0.22 Ma) and Rio Pichileufu (47.46 ± 0.05 Ma). The improved age control makes possible a finer scale of evolutionary hypothesis testing and turnover analysis in the region. The age is concordant with the site's placement in the Huitrera Formation and a depositional origin related to Early Paleogene arc volcanism, and it correlates to an interval of significant climate fluctuations following the Paleocene-Eocene boundary. ©Asociación Paleontológica Argentina. Fil:Zamaloa, M.D.C. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. Fil:Rubén Cúneo, N. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. JOUR info:eu-repo/semantics/openAccess http://creativecommons.org/licenses/by/2.5/ar http://hdl.handle.net/20.500.12110/paper_00027014_v47_n2_p207_Wilf |
| institution |
Universidad de Buenos Aires |
| institution_str |
I-28 |
| repository_str |
R-134 |
| collection |
Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) |
| topic |
Argentina Early eocene Geochronology Huitrera formation Neuquén Paleobotany Patagonia age determination argon isotope biostratigraphy biotite climate variation Eocene fossil assemblage frog geochronology hypothesis testing insect mudstone ontogeny paleobotany Paleocene-Eocene boundary plant sandstone sanidine volcanism Argentina Nahuel Huapi Lake Anura Hexapoda Pipidae |
| spellingShingle |
Argentina Early eocene Geochronology Huitrera formation Neuquén Paleobotany Patagonia age determination argon isotope biostratigraphy biotite climate variation Eocene fossil assemblage frog geochronology hypothesis testing insect mudstone ontogeny paleobotany Paleocene-Eocene boundary plant sandstone sanidine volcanism Argentina Nahuel Huapi Lake Anura Hexapoda Pipidae Wilf, P. Singer, B.S. Zamaloa, M.D.C. Johnson, K.R. Rubén Cúneo, N. Early eocene 40Ar/39Ar age for the Pampa de Jones plant, frog, and insect biota (Huitrera Formation, Neuquén Province, Patagonia, Argentina) |
| topic_facet |
Argentina Early eocene Geochronology Huitrera formation Neuquén Paleobotany Patagonia age determination argon isotope biostratigraphy biotite climate variation Eocene fossil assemblage frog geochronology hypothesis testing insect mudstone ontogeny paleobotany Paleocene-Eocene boundary plant sandstone sanidine volcanism Argentina Nahuel Huapi Lake Anura Hexapoda Pipidae |
| description |
The Pampa de Jones fossil site, a stratigraphically isolated roadcut near the northeastern shore of Nahuel Huapi Lake in Neuquén Province, Argentina, holds a rich fossil biota including a macroflora, a microflora, insects, and most famously, an ontogenetic series of pipid frogs. The site exposes tuffaceous mudstone and sandstone beds of probable lacustrine origin, considered to belong to the volcanic Huitrera Formation. However, there have been no reliable age constraints for the fossil assemblage. We undertook laser fusion analyses of sanidine and biotite crystals occurring in a tuff layer found 4.4 m above the main fossil horizon. Twentyeight sanidine crystals yielded an 40ArZ39Ar age of 54.24 ± 0.45 Ma that is preferred over our biotite age of 53.64 ± 0.35 Ma. Pampa de Jones is thus the oldest well-dated Eocene fossil site in Patagonia, predating two other recently 40Ar/39Ar-dated sites: Laguna del Hunco (51.91 ± 0.22 Ma) and Rio Pichileufu (47.46 ± 0.05 Ma). The improved age control makes possible a finer scale of evolutionary hypothesis testing and turnover analysis in the region. The age is concordant with the site's placement in the Huitrera Formation and a depositional origin related to Early Paleogene arc volcanism, and it correlates to an interval of significant climate fluctuations following the Paleocene-Eocene boundary. ©Asociación Paleontológica Argentina. |
| format |
JOUR |
| author |
Wilf, P. Singer, B.S. Zamaloa, M.D.C. Johnson, K.R. Rubén Cúneo, N. |
| author_facet |
Wilf, P. Singer, B.S. Zamaloa, M.D.C. Johnson, K.R. Rubén Cúneo, N. |
| author_sort |
Wilf, P. |
| title |
Early eocene 40Ar/39Ar age for the Pampa de Jones plant, frog, and insect biota (Huitrera Formation, Neuquén Province, Patagonia, Argentina) |
| title_short |
Early eocene 40Ar/39Ar age for the Pampa de Jones plant, frog, and insect biota (Huitrera Formation, Neuquén Province, Patagonia, Argentina) |
| title_full |
Early eocene 40Ar/39Ar age for the Pampa de Jones plant, frog, and insect biota (Huitrera Formation, Neuquén Province, Patagonia, Argentina) |
| title_fullStr |
Early eocene 40Ar/39Ar age for the Pampa de Jones plant, frog, and insect biota (Huitrera Formation, Neuquén Province, Patagonia, Argentina) |
| title_full_unstemmed |
Early eocene 40Ar/39Ar age for the Pampa de Jones plant, frog, and insect biota (Huitrera Formation, Neuquén Province, Patagonia, Argentina) |
| title_sort |
early eocene 40ar/39ar age for the pampa de jones plant, frog, and insect biota (huitrera formation, neuquén province, patagonia, argentina) |
| url |
http://hdl.handle.net/20.500.12110/paper_00027014_v47_n2_p207_Wilf |
| work_keys_str_mv |
AT wilfp earlyeocene40ar39arageforthepampadejonesplantfrogandinsectbiotahuitreraformationneuquenprovincepatagoniaargentina AT singerbs earlyeocene40ar39arageforthepampadejonesplantfrogandinsectbiotahuitreraformationneuquenprovincepatagoniaargentina AT zamaloamdc earlyeocene40ar39arageforthepampadejonesplantfrogandinsectbiotahuitreraformationneuquenprovincepatagoniaargentina AT johnsonkr earlyeocene40ar39arageforthepampadejonesplantfrogandinsectbiotahuitreraformationneuquenprovincepatagoniaargentina AT rubencuneon earlyeocene40ar39arageforthepampadejonesplantfrogandinsectbiotahuitreraformationneuquenprovincepatagoniaargentina |
| _version_ |
1807323870297849856 |