Petrology and geochemistry of Carboniferous siliciclastics from the Argentine Frontal Cordillera: A test of methods for interpreting provenance and tectonic setting
Petrological and geochemical characteristics of sandstones and shales from the Carboniferous Cerro Agua Negra Formation (Río Blanco basin, western Argentina) are discussed. The sandstones are mostly feldspathic litharenites with subordinate litharenites and lithic arkoses, and their modal compositio...
Guardado en:
| Autores principales: | , , |
|---|---|
| Formato: | JOUR |
| Materias: | |
| Acceso en línea: | http://hdl.handle.net/20.500.12110/paper_08959811_v36_n_p32_Spalletti |
| Aporte de: |
| id |
todo:paper_08959811_v36_n_p32_Spalletti |
|---|---|
| record_format |
dspace |
| spelling |
todo:paper_08959811_v36_n_p32_Spalletti2023-10-03T15:43:03Z Petrology and geochemistry of Carboniferous siliciclastics from the Argentine Frontal Cordillera: A test of methods for interpreting provenance and tectonic setting Spalletti, L.A. Limarino, C.O. Piñol, F.C. Argentina Carboniferous Río Blanco Basin Sandstone petrology Sedimentary geochemistry Carboniferous chemical alteration chemical composition continental crust feldspar felsic rock lithology metasedimentary rock petrology plutonic rock provenance rare earth element remobilization sandstone sediment chemistry siliciclastic deposit source rock tectonic setting Argentina Blanco Basin Petrological and geochemical characteristics of sandstones and shales from the Carboniferous Cerro Agua Negra Formation (Río Blanco basin, western Argentina) are discussed. The sandstones are mostly feldspathic litharenites with subordinate litharenites and lithic arkoses, and their modal compositions indicate two major sources. The first represents a recycled orogen and can be identified as the Protoprecordillera, a N-S trending mountainous area that separated the Paganzo and Río Blanco basins and that was a positive element at least up until the end of the Carboniferous. The second was further east, in the Sierras Pampeanas terrane. It consisted of a variety of metasedimentary and felsic plutonic crystalline rocks. The Protoprecordillera must have been crossed by transverse valleys that facilitated the transfer of Pampean terrigenous material towards the Río Blanco basin. A lack of volcanogenic sand suggests that the basin was open towards proto-Pacific in the west, rather than being separated from it by a magmatic arc as previously suggested.Bulk geochemical analysis of different lithological types (arenites, wackes and shales) demonstrates a strong relationship between texture and chemical composition of the rocks, even taking into account the immobile elements. The largest differences are between shales and arenites, while the wackes have intermediate compositions. The CIA (chemical index of alteration) indicates partial remobilisation of oxides from source rocks and enrichment of aluminium and potassium in the shales, which reflects their potassic clay mineral composition. Overall, siliciclastics of the Cerro Agua Negra Formation have a similar composition to the upper continental crust (with slight net enrichment of SiO 2 in the arenites and of Al 2O 3 in the shales). Rare earth element profiles reflect terrigenous contributions, since they are enriched in light-REE, have a pronounced negative Eu anomaly and a relative depletion of the heavy-REE. The results show that discrimination plots commonly employed to infer provenance and tectonic setting from siliclastics are compromised where bulk chemical composition is strongly dependent on grain size and sorting. © 2011 Elsevier Ltd. Fil:Limarino, C.O. 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_08959811_v36_n_p32_Spalletti |
| 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 Carboniferous Río Blanco Basin Sandstone petrology Sedimentary geochemistry Carboniferous chemical alteration chemical composition continental crust feldspar felsic rock lithology metasedimentary rock petrology plutonic rock provenance rare earth element remobilization sandstone sediment chemistry siliciclastic deposit source rock tectonic setting Argentina Blanco Basin |
| spellingShingle |
Argentina Carboniferous Río Blanco Basin Sandstone petrology Sedimentary geochemistry Carboniferous chemical alteration chemical composition continental crust feldspar felsic rock lithology metasedimentary rock petrology plutonic rock provenance rare earth element remobilization sandstone sediment chemistry siliciclastic deposit source rock tectonic setting Argentina Blanco Basin Spalletti, L.A. Limarino, C.O. Piñol, F.C. Petrology and geochemistry of Carboniferous siliciclastics from the Argentine Frontal Cordillera: A test of methods for interpreting provenance and tectonic setting |
| topic_facet |
Argentina Carboniferous Río Blanco Basin Sandstone petrology Sedimentary geochemistry Carboniferous chemical alteration chemical composition continental crust feldspar felsic rock lithology metasedimentary rock petrology plutonic rock provenance rare earth element remobilization sandstone sediment chemistry siliciclastic deposit source rock tectonic setting Argentina Blanco Basin |
| description |
Petrological and geochemical characteristics of sandstones and shales from the Carboniferous Cerro Agua Negra Formation (Río Blanco basin, western Argentina) are discussed. The sandstones are mostly feldspathic litharenites with subordinate litharenites and lithic arkoses, and their modal compositions indicate two major sources. The first represents a recycled orogen and can be identified as the Protoprecordillera, a N-S trending mountainous area that separated the Paganzo and Río Blanco basins and that was a positive element at least up until the end of the Carboniferous. The second was further east, in the Sierras Pampeanas terrane. It consisted of a variety of metasedimentary and felsic plutonic crystalline rocks. The Protoprecordillera must have been crossed by transverse valleys that facilitated the transfer of Pampean terrigenous material towards the Río Blanco basin. A lack of volcanogenic sand suggests that the basin was open towards proto-Pacific in the west, rather than being separated from it by a magmatic arc as previously suggested.Bulk geochemical analysis of different lithological types (arenites, wackes and shales) demonstrates a strong relationship between texture and chemical composition of the rocks, even taking into account the immobile elements. The largest differences are between shales and arenites, while the wackes have intermediate compositions. The CIA (chemical index of alteration) indicates partial remobilisation of oxides from source rocks and enrichment of aluminium and potassium in the shales, which reflects their potassic clay mineral composition. Overall, siliciclastics of the Cerro Agua Negra Formation have a similar composition to the upper continental crust (with slight net enrichment of SiO 2 in the arenites and of Al 2O 3 in the shales). Rare earth element profiles reflect terrigenous contributions, since they are enriched in light-REE, have a pronounced negative Eu anomaly and a relative depletion of the heavy-REE. The results show that discrimination plots commonly employed to infer provenance and tectonic setting from siliclastics are compromised where bulk chemical composition is strongly dependent on grain size and sorting. © 2011 Elsevier Ltd. |
| format |
JOUR |
| author |
Spalletti, L.A. Limarino, C.O. Piñol, F.C. |
| author_facet |
Spalletti, L.A. Limarino, C.O. Piñol, F.C. |
| author_sort |
Spalletti, L.A. |
| title |
Petrology and geochemistry of Carboniferous siliciclastics from the Argentine Frontal Cordillera: A test of methods for interpreting provenance and tectonic setting |
| title_short |
Petrology and geochemistry of Carboniferous siliciclastics from the Argentine Frontal Cordillera: A test of methods for interpreting provenance and tectonic setting |
| title_full |
Petrology and geochemistry of Carboniferous siliciclastics from the Argentine Frontal Cordillera: A test of methods for interpreting provenance and tectonic setting |
| title_fullStr |
Petrology and geochemistry of Carboniferous siliciclastics from the Argentine Frontal Cordillera: A test of methods for interpreting provenance and tectonic setting |
| title_full_unstemmed |
Petrology and geochemistry of Carboniferous siliciclastics from the Argentine Frontal Cordillera: A test of methods for interpreting provenance and tectonic setting |
| title_sort |
petrology and geochemistry of carboniferous siliciclastics from the argentine frontal cordillera: a test of methods for interpreting provenance and tectonic setting |
| url |
http://hdl.handle.net/20.500.12110/paper_08959811_v36_n_p32_Spalletti |
| work_keys_str_mv |
AT spallettila petrologyandgeochemistryofcarboniferoussiliciclasticsfromtheargentinefrontalcordilleraatestofmethodsforinterpretingprovenanceandtectonicsetting AT limarinoco petrologyandgeochemistryofcarboniferoussiliciclasticsfromtheargentinefrontalcordilleraatestofmethodsforinterpretingprovenanceandtectonicsetting AT pinolfc petrologyandgeochemistryofcarboniferoussiliciclasticsfromtheargentinefrontalcordilleraatestofmethodsforinterpretingprovenanceandtectonicsetting |
| _version_ |
1807321675119722496 |