New insights into petrogenesis of Miocene magmatism associated with porphyry copper deposits of the Andean Pampean flat slab, Argentina
The Paramillos de Uspallata mining district located in the backarc region of the Pampean flat-slab segment (28°–33°S) features porphyry-type deposits genetically associated with Middle Miocene volcanics. This mineralizing magmatism comprising hydrothermally altered (sodic-calcic, potassic and phylli...
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2018
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| Acceso en línea: | https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_16749871_v9_n5_p1565_Carrasquero http://hdl.handle.net/20.500.12110/paper_16749871_v9_n5_p1565_Carrasquero |
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paper:paper_16749871_v9_n5_p1565_Carrasquero2023-06-08T16:26:27Z New insights into petrogenesis of Miocene magmatism associated with porphyry copper deposits of the Andean Pampean flat slab, Argentina Adakitic signal Backarc Central Andes Petrogenesis Porphyry copper deposits backarc basin copper crustal thickness magmatism mining Miocene ore deposit petrogenesis porphyry Andes Argentina Sierras Pampeanas The Paramillos de Uspallata mining district located in the backarc region of the Pampean flat-slab segment (28°–33°S) features porphyry-type deposits genetically associated with Middle Miocene volcanics. This mineralizing magmatism comprising hydrothermally altered (sodic-calcic, potassic and phyllic alteration) subvolcanic and pyroclastic rocks of andesite-basaltic andesite and dacite-rhyolite composition with a typical arc signature, represents the eastward broadening of the Farellones arc by ∼17 Ma. Its geochemistry also reveals a residual mineralogy of amphibole ± garnet with limited plagioclase fractionation resulting in an adakitic signal; however, according to the isotopic data collected in our study, the contributions of MASH (melting-assimilation-storage-homogenization) processes in the acquisition of this signal cannot be disregarded. Both the broadening of the Farellones arc and its residual mineralogy – typical of relatively deep magmatic chambers – are consistent with a slab shallowing and outcoming crustal thickening setting. This tectonic scenario could be interpreted as a result of an early effect of the Juan Fernandez Ridge collision that was further to the north by ∼17 Ma. Our findings suggest that magmas were fertile for porphyry type deposits during the early stages of the slab shallowing. © 2017 China University of Geosciences (Beijing) and Peking University 2018 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_16749871_v9_n5_p1565_Carrasquero http://hdl.handle.net/20.500.12110/paper_16749871_v9_n5_p1565_Carrasquero |
| institution |
Universidad de Buenos Aires |
| institution_str |
I-28 |
| repository_str |
R-134 |
| collection |
Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) |
| topic |
Adakitic signal Backarc Central Andes Petrogenesis Porphyry copper deposits backarc basin copper crustal thickness magmatism mining Miocene ore deposit petrogenesis porphyry Andes Argentina Sierras Pampeanas |
| spellingShingle |
Adakitic signal Backarc Central Andes Petrogenesis Porphyry copper deposits backarc basin copper crustal thickness magmatism mining Miocene ore deposit petrogenesis porphyry Andes Argentina Sierras Pampeanas New insights into petrogenesis of Miocene magmatism associated with porphyry copper deposits of the Andean Pampean flat slab, Argentina |
| topic_facet |
Adakitic signal Backarc Central Andes Petrogenesis Porphyry copper deposits backarc basin copper crustal thickness magmatism mining Miocene ore deposit petrogenesis porphyry Andes Argentina Sierras Pampeanas |
| description |
The Paramillos de Uspallata mining district located in the backarc region of the Pampean flat-slab segment (28°–33°S) features porphyry-type deposits genetically associated with Middle Miocene volcanics. This mineralizing magmatism comprising hydrothermally altered (sodic-calcic, potassic and phyllic alteration) subvolcanic and pyroclastic rocks of andesite-basaltic andesite and dacite-rhyolite composition with a typical arc signature, represents the eastward broadening of the Farellones arc by ∼17 Ma. Its geochemistry also reveals a residual mineralogy of amphibole ± garnet with limited plagioclase fractionation resulting in an adakitic signal; however, according to the isotopic data collected in our study, the contributions of MASH (melting-assimilation-storage-homogenization) processes in the acquisition of this signal cannot be disregarded. Both the broadening of the Farellones arc and its residual mineralogy – typical of relatively deep magmatic chambers – are consistent with a slab shallowing and outcoming crustal thickening setting. This tectonic scenario could be interpreted as a result of an early effect of the Juan Fernandez Ridge collision that was further to the north by ∼17 Ma. Our findings suggest that magmas were fertile for porphyry type deposits during the early stages of the slab shallowing. © 2017 China University of Geosciences (Beijing) and Peking University |
| title |
New insights into petrogenesis of Miocene magmatism associated with porphyry copper deposits of the Andean Pampean flat slab, Argentina |
| title_short |
New insights into petrogenesis of Miocene magmatism associated with porphyry copper deposits of the Andean Pampean flat slab, Argentina |
| title_full |
New insights into petrogenesis of Miocene magmatism associated with porphyry copper deposits of the Andean Pampean flat slab, Argentina |
| title_fullStr |
New insights into petrogenesis of Miocene magmatism associated with porphyry copper deposits of the Andean Pampean flat slab, Argentina |
| title_full_unstemmed |
New insights into petrogenesis of Miocene magmatism associated with porphyry copper deposits of the Andean Pampean flat slab, Argentina |
| title_sort |
new insights into petrogenesis of miocene magmatism associated with porphyry copper deposits of the andean pampean flat slab, argentina |
| publishDate |
2018 |
| url |
https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_16749871_v9_n5_p1565_Carrasquero http://hdl.handle.net/20.500.12110/paper_16749871_v9_n5_p1565_Carrasquero |
| _version_ |
1768546648200314880 |