The southern segment of the Famatinian magmatic arc, La Pampa Province, Argentina
The present study led to the identification of a largely hidden southern segment of the Famatinian magmatic arc in the province of la Pampa, south-central Argentina. The arc is represented by scarce outcrops of metaigneous rocks (mostly meta-quartz-diorites and metagabbros) but stands out in the aer...
| Main Authors: | , , , , |
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| Format: | Journal Article |
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Elsevier Science BV
2010
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| Online Access: | http://hdl.handle.net/20.500.11937/41878 |
| _version_ | 1848756266251321344 |
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| author | Chernicoff, C. Zappettini, E. Santos, J. Allchurch, S. McNaughton, Neal |
| author_facet | Chernicoff, C. Zappettini, E. Santos, J. Allchurch, S. McNaughton, Neal |
| author_sort | Chernicoff, C. |
| building | Curtin Institutional Repository |
| collection | Online Access |
| description | The present study led to the identification of a largely hidden southern segment of the Famatinian magmatic arc in the province of la Pampa, south-central Argentina. The arc is represented by scarce outcrops of metaigneous rocks (mostly meta-quartz-diorites and metagabbros) but stands out in the aeromagnetic data as a conspicuous and continuous, NNW-trending magnetic anomaly. The geochemical signature of this magmatic suite points to a pre-collisional continental magmatic arc. Its crystallization age (U-Pb SHRIMP dating on magmatic zircon) ranges from ca. 476 to 466 Ma, being comparable, therefore, to the central and northern segments of the Famatinian arc. All dated zircon of the metagabbro have similar Hf-176/Hf-177 ratios, negative e(Hf) (from -5.02 to -3.62) and average Lu-Hf model ages of ca. 1.7 Ga, indicating a crustal contamination of a mantle-derived mafic magma (of ca. 466 Ma) with much older rocks, probably older than 2 Ga, hence suggesting that part of the underlying basement of the southernmost Pampia terrane is at least this old. U-Pb SHRIMP dating on metamorphic zircon rims/areas yielded ca 454 Ma. that is within the 465-450 Ma age range of Famatinian metamorphism previously recorded in La Pampa. The amphibolite-facies metamorphism that affects the magmatic arc in la Pampa is attributed to the collision of the Cuyania (greater Precordillera) terrane against the western margin of Gondwana. |
| first_indexed | 2025-11-14T09:09:28Z |
| format | Journal Article |
| id | curtin-20.500.11937-41878 |
| institution | Curtin University Malaysia |
| institution_category | Local University |
| last_indexed | 2025-11-14T09:09:28Z |
| publishDate | 2010 |
| publisher | Elsevier Science BV |
| recordtype | eprints |
| repository_type | Digital Repository |
| spelling | curtin-20.500.11937-418782017-09-13T16:05:51Z The southern segment of the Famatinian magmatic arc, La Pampa Province, Argentina Chernicoff, C. Zappettini, E. Santos, J. Allchurch, S. McNaughton, Neal Cuyania Nw Argentina Precordillera Terrane Sierras-Pampeanas Gondwana Geophysical Evidence Age Constraints Pie-De-Palo Evolution San-Luis The present study led to the identification of a largely hidden southern segment of the Famatinian magmatic arc in the province of la Pampa, south-central Argentina. The arc is represented by scarce outcrops of metaigneous rocks (mostly meta-quartz-diorites and metagabbros) but stands out in the aeromagnetic data as a conspicuous and continuous, NNW-trending magnetic anomaly. The geochemical signature of this magmatic suite points to a pre-collisional continental magmatic arc. Its crystallization age (U-Pb SHRIMP dating on magmatic zircon) ranges from ca. 476 to 466 Ma, being comparable, therefore, to the central and northern segments of the Famatinian arc. All dated zircon of the metagabbro have similar Hf-176/Hf-177 ratios, negative e(Hf) (from -5.02 to -3.62) and average Lu-Hf model ages of ca. 1.7 Ga, indicating a crustal contamination of a mantle-derived mafic magma (of ca. 466 Ma) with much older rocks, probably older than 2 Ga, hence suggesting that part of the underlying basement of the southernmost Pampia terrane is at least this old. U-Pb SHRIMP dating on metamorphic zircon rims/areas yielded ca 454 Ma. that is within the 465-450 Ma age range of Famatinian metamorphism previously recorded in La Pampa. The amphibolite-facies metamorphism that affects the magmatic arc in la Pampa is attributed to the collision of the Cuyania (greater Precordillera) terrane against the western margin of Gondwana. 2010 Journal Article http://hdl.handle.net/20.500.11937/41878 10.1016/j.gr.2009.10.008 Elsevier Science BV restricted |
| spellingShingle | Cuyania Nw Argentina Precordillera Terrane Sierras-Pampeanas Gondwana Geophysical Evidence Age Constraints Pie-De-Palo Evolution San-Luis Chernicoff, C. Zappettini, E. Santos, J. Allchurch, S. McNaughton, Neal The southern segment of the Famatinian magmatic arc, La Pampa Province, Argentina |
| title | The southern segment of the Famatinian magmatic arc, La Pampa Province, Argentina |
| title_full | The southern segment of the Famatinian magmatic arc, La Pampa Province, Argentina |
| title_fullStr | The southern segment of the Famatinian magmatic arc, La Pampa Province, Argentina |
| title_full_unstemmed | The southern segment of the Famatinian magmatic arc, La Pampa Province, Argentina |
| title_short | The southern segment of the Famatinian magmatic arc, La Pampa Province, Argentina |
| title_sort | southern segment of the famatinian magmatic arc, la pampa province, argentina |
| topic | Cuyania Nw Argentina Precordillera Terrane Sierras-Pampeanas Gondwana Geophysical Evidence Age Constraints Pie-De-Palo Evolution San-Luis |
| url | http://hdl.handle.net/20.500.11937/41878 |