Fossiliferous diamicts (Miocene-Pleistocene): Belén, Gage and Terrapin Formations on the James Ross Island, Antarctica
Late Cenozoic fossiliferous diamicts, cropping out on the eastern part of James Ross Island (north-east Antarctic Peninsula) comprise three new lithostratigraphic units. The Belén and Terrapin formations crop out on the south and west coast of Belén Fjord (Lat. 64° 00′ S, Long. 57° 31′ W), respectiv...
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2003
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| Acceso en línea: | https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00044822_v58_n3_p298_Lirio http://hdl.handle.net/20.500.12110/paper_00044822_v58_n3_p298_Lirio |
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paper:paper_00044822_v58_n3_p298_Lirio2025-07-30T17:09:26Z Fossiliferous diamicts (Miocene-Pleistocene): Belén, Gage and Terrapin Formations on the James Ross Island, Antarctica Antarctica James Ross Basin Lithostratigraphy Micropaleontology Neogene argon-argon dating diamicton lithostratigraphy Miocene Pleistocene Pliocene Antarctic Peninsula Antarctica Arctic and Antarctic James Ross Island West Antarctica World Late Cenozoic fossiliferous diamicts, cropping out on the eastern part of James Ross Island (north-east Antarctic Peninsula) comprise three new lithostratigraphic units. The Belén and Terrapin formations crop out on the south and west coast of Belén Fjord (Lat. 64° 00′ S, Long. 57° 31′ W), respectively, and the Gage Formation is exposed on the south coast of Cape Gage (Lat. 64° 12′ S, Long. 57° 06′ W). Shells of pectinids from the Belén and Terrapin formations were dated using 87 Sr/ 86Sr isotopes, yielding a Late Miocene age (6.8 ± 0.5 Ma) and a Late Pliocene-Early Pleistocene age (1.95 + 1.12/-0.52 Ma), respectively. The Gage Formation is thought to be Late Pliocene in age, younger than 3.1 ± 0.3 My on the basis of 40Ar/ 3Ar dating performed on a basalt clast included in the sediments and no older than 2.4 Ma based on the presence of Zygochlamys anderssoni. The micropalcontological content of these formations is compared with those of other cenozoic fossiliferous deposits from the James Ross Basin, and the importance of the paleoenvironmental evidence obtained from this correlation is discussed in relation to the present knowledge of Late Miocene - Pleistocene lithostratigraphy and climate evolution of Antarctica. Diamicts of the Belén and Terrapin formations and alkaline volcanic rocks of the James Ross Island Volcanic Group (JRIVG) are interbedded on the coast of Belén Fjord, where the oldest known volcanic rocks of the JRIVG are dated at 9.2 ± 0.3 Ma (40Ar/39Ar). This age confirms a Late Miocene initiation of volcanic activities on James Ross Island and the importance of the Belén Fjord area for further studies of the early stages of Late Cenozoic tectonic and magmatic evolution of the Larsen Basin. © 2003 Associación Geológica Argentina. 2003 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00044822_v58_n3_p298_Lirio http://hdl.handle.net/20.500.12110/paper_00044822_v58_n3_p298_Lirio |
| institution |
Universidad de Buenos Aires |
| institution_str |
I-28 |
| repository_str |
R-134 |
| collection |
Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) |
| topic |
Antarctica James Ross Basin Lithostratigraphy Micropaleontology Neogene argon-argon dating diamicton lithostratigraphy Miocene Pleistocene Pliocene Antarctic Peninsula Antarctica Arctic and Antarctic James Ross Island West Antarctica World |
| spellingShingle |
Antarctica James Ross Basin Lithostratigraphy Micropaleontology Neogene argon-argon dating diamicton lithostratigraphy Miocene Pleistocene Pliocene Antarctic Peninsula Antarctica Arctic and Antarctic James Ross Island West Antarctica World Fossiliferous diamicts (Miocene-Pleistocene): Belén, Gage and Terrapin Formations on the James Ross Island, Antarctica |
| topic_facet |
Antarctica James Ross Basin Lithostratigraphy Micropaleontology Neogene argon-argon dating diamicton lithostratigraphy Miocene Pleistocene Pliocene Antarctic Peninsula Antarctica Arctic and Antarctic James Ross Island West Antarctica World |
| description |
Late Cenozoic fossiliferous diamicts, cropping out on the eastern part of James Ross Island (north-east Antarctic Peninsula) comprise three new lithostratigraphic units. The Belén and Terrapin formations crop out on the south and west coast of Belén Fjord (Lat. 64° 00′ S, Long. 57° 31′ W), respectively, and the Gage Formation is exposed on the south coast of Cape Gage (Lat. 64° 12′ S, Long. 57° 06′ W). Shells of pectinids from the Belén and Terrapin formations were dated using 87 Sr/ 86Sr isotopes, yielding a Late Miocene age (6.8 ± 0.5 Ma) and a Late Pliocene-Early Pleistocene age (1.95 + 1.12/-0.52 Ma), respectively. The Gage Formation is thought to be Late Pliocene in age, younger than 3.1 ± 0.3 My on the basis of 40Ar/ 3Ar dating performed on a basalt clast included in the sediments and no older than 2.4 Ma based on the presence of Zygochlamys anderssoni. The micropalcontological content of these formations is compared with those of other cenozoic fossiliferous deposits from the James Ross Basin, and the importance of the paleoenvironmental evidence obtained from this correlation is discussed in relation to the present knowledge of Late Miocene - Pleistocene lithostratigraphy and climate evolution of Antarctica. Diamicts of the Belén and Terrapin formations and alkaline volcanic rocks of the James Ross Island Volcanic Group (JRIVG) are interbedded on the coast of Belén Fjord, where the oldest known volcanic rocks of the JRIVG are dated at 9.2 ± 0.3 Ma (40Ar/39Ar). This age confirms a Late Miocene initiation of volcanic activities on James Ross Island and the importance of the Belén Fjord area for further studies of the early stages of Late Cenozoic tectonic and magmatic evolution of the Larsen Basin. © 2003 Associación Geológica Argentina. |
| title |
Fossiliferous diamicts (Miocene-Pleistocene): Belén, Gage and Terrapin Formations on the James Ross Island, Antarctica |
| title_short |
Fossiliferous diamicts (Miocene-Pleistocene): Belén, Gage and Terrapin Formations on the James Ross Island, Antarctica |
| title_full |
Fossiliferous diamicts (Miocene-Pleistocene): Belén, Gage and Terrapin Formations on the James Ross Island, Antarctica |
| title_fullStr |
Fossiliferous diamicts (Miocene-Pleistocene): Belén, Gage and Terrapin Formations on the James Ross Island, Antarctica |
| title_full_unstemmed |
Fossiliferous diamicts (Miocene-Pleistocene): Belén, Gage and Terrapin Formations on the James Ross Island, Antarctica |
| title_sort |
fossiliferous diamicts (miocene-pleistocene): belén, gage and terrapin formations on the james ross island, antarctica |
| publishDate |
2003 |
| url |
https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00044822_v58_n3_p298_Lirio http://hdl.handle.net/20.500.12110/paper_00044822_v58_n3_p298_Lirio |
| _version_ |
1840328548597891072 |