Within plate seismicity analysis in the segment between the high Cordillera and the Precordillera of northern Mendoza (Southern Central Andes)
Crustal seismicity in northwestern Mendoza Province in Argentina, corresponding to the transition zone between the Chilean-Pampean flat subduction zone (26.5–33.5°S) and the Southern Central Andes normal subduction zone to the south, is studied in order to i) identify its relationship with the mappe...
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| Format: | Article |
| Language: | English |
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KeAi Communications Co., Ltd.
2018-01-01
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| Series: | Geodesy and Geodynamics |
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| Online Access: | http://www.sciencedirect.com/science/article/pii/S167498471730109X |
| _version_ | 1818720255263899648 |
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| author | Julián Olivar Silvina Nacif Lucas Fennell Andrés Folguera |
| author_facet | Julián Olivar Silvina Nacif Lucas Fennell Andrés Folguera |
| author_sort | Julián Olivar |
| collection | DOAJ |
| description | Crustal seismicity in northwestern Mendoza Province in Argentina, corresponding to the transition zone between the Chilean-Pampean flat subduction zone (26.5–33.5°S) and the Southern Central Andes normal subduction zone to the south, is studied in order to i) identify its relationship with the mapped structure, ii) determine deformational mechanisms and iii) constrain the geometry of the fold and thrust belt in the lower crust. Through this, we aim to determine which are the structures that contribute to Andean construction, east of the Frontal Cordillera in Argentina and at the western Principal Cordillera in Chile. Data from a temporary local seismic network are reprocessed in order to achieve a precise location of hypocenters and, whenever possible, to build focal mechanisms. Results are interpreted and compared with previous seismic studies and structural models. Analyzed seismicity is grouped around the eastern front of Frontal Cordillera, with hypocenters mainly at depths of 25–40 km. Contrastingly, earthquakes in the Principal Cordillera to the west are located at the axial Andean sector and Chilean slope, with depths shallower than 15 km. Obtained focal mechanisms indicate mainly strike-slip displacements, left lateral at Frontal Cordillera and right lateral at Principal Cordillera. Based on these observations, new possible structural models are proposed, where seismogenic sources could be either associated with inherited basement structures from the Cuyania-Chilenia suture; or correspond to deep-blind thrusts linked with a deeper-than-previously-assumed decollement that could be shared between Frontal Cordillera and western Precordillera. This deeper decollement would coincide in turn with the one determined from receiver function analysis for the eastern Sierras Pampeanas in previous works, potentially implying a common decollement all through the fold and thrust belt configuration. Apart from this, a new interpretation of seismogenic structures in Principal Cordillera near the Argentina–Chile boundary is provided. |
| first_indexed | 2024-12-17T20:19:56Z |
| format | Article |
| id | doaj.art-5ae07f57b5914de58f1f44dc737e47a9 |
| institution | Directory Open Access Journal |
| issn | 1674-9847 |
| language | English |
| last_indexed | 2024-12-17T20:19:56Z |
| publishDate | 2018-01-01 |
| publisher | KeAi Communications Co., Ltd. |
| record_format | Article |
| series | Geodesy and Geodynamics |
| spelling | doaj.art-5ae07f57b5914de58f1f44dc737e47a92022-12-21T21:33:59ZengKeAi Communications Co., Ltd.Geodesy and Geodynamics1674-98472018-01-0191132410.1016/j.geog.2017.09.004Within plate seismicity analysis in the segment between the high Cordillera and the Precordillera of northern Mendoza (Southern Central Andes)Julián Olivar0Silvina Nacif1Lucas Fennell2Andrés Folguera3CONICET – Universidad de Buenos Aires, Instituto de Estudios Andinos ‘Don Pablo Groeber’ (IDEAN), Facultad de Ciencias Exactas y Naturales, Pabellón II, Ciudad Universitaria, Buenos Aires, C1428EGA, ArgentinaCONICET – Instituto Geofísico-Sismológico ‘Ing. F.S. Volponi’ (IGSV), Ruta 12 km17 Jardín de los Poetas Marquesado, Rivadavia, Provincia de San Juan, ArgentinaCONICET – Universidad de Buenos Aires, Instituto de Estudios Andinos ‘Don Pablo Groeber’ (IDEAN), Facultad de Ciencias Exactas y Naturales, Pabellón II, Ciudad Universitaria, Buenos Aires, C1428EGA, ArgentinaCONICET – Universidad de Buenos Aires, Instituto de Estudios Andinos ‘Don Pablo Groeber’ (IDEAN), Facultad de Ciencias Exactas y Naturales, Pabellón II, Ciudad Universitaria, Buenos Aires, C1428EGA, ArgentinaCrustal seismicity in northwestern Mendoza Province in Argentina, corresponding to the transition zone between the Chilean-Pampean flat subduction zone (26.5–33.5°S) and the Southern Central Andes normal subduction zone to the south, is studied in order to i) identify its relationship with the mapped structure, ii) determine deformational mechanisms and iii) constrain the geometry of the fold and thrust belt in the lower crust. Through this, we aim to determine which are the structures that contribute to Andean construction, east of the Frontal Cordillera in Argentina and at the western Principal Cordillera in Chile. Data from a temporary local seismic network are reprocessed in order to achieve a precise location of hypocenters and, whenever possible, to build focal mechanisms. Results are interpreted and compared with previous seismic studies and structural models. Analyzed seismicity is grouped around the eastern front of Frontal Cordillera, with hypocenters mainly at depths of 25–40 km. Contrastingly, earthquakes in the Principal Cordillera to the west are located at the axial Andean sector and Chilean slope, with depths shallower than 15 km. Obtained focal mechanisms indicate mainly strike-slip displacements, left lateral at Frontal Cordillera and right lateral at Principal Cordillera. Based on these observations, new possible structural models are proposed, where seismogenic sources could be either associated with inherited basement structures from the Cuyania-Chilenia suture; or correspond to deep-blind thrusts linked with a deeper-than-previously-assumed decollement that could be shared between Frontal Cordillera and western Precordillera. This deeper decollement would coincide in turn with the one determined from receiver function analysis for the eastern Sierras Pampeanas in previous works, potentially implying a common decollement all through the fold and thrust belt configuration. Apart from this, a new interpretation of seismogenic structures in Principal Cordillera near the Argentina–Chile boundary is provided.http://www.sciencedirect.com/science/article/pii/S167498471730109XCrustal seismicitySeismogenic structuresFrontal cordilleraBlind thrustsDecollement |
| spellingShingle | Julián Olivar Silvina Nacif Lucas Fennell Andrés Folguera Within plate seismicity analysis in the segment between the high Cordillera and the Precordillera of northern Mendoza (Southern Central Andes) Geodesy and Geodynamics Crustal seismicity Seismogenic structures Frontal cordillera Blind thrusts Decollement |
| title | Within plate seismicity analysis in the segment between the high Cordillera and the Precordillera of northern Mendoza (Southern Central Andes) |
| title_full | Within plate seismicity analysis in the segment between the high Cordillera and the Precordillera of northern Mendoza (Southern Central Andes) |
| title_fullStr | Within plate seismicity analysis in the segment between the high Cordillera and the Precordillera of northern Mendoza (Southern Central Andes) |
| title_full_unstemmed | Within plate seismicity analysis in the segment between the high Cordillera and the Precordillera of northern Mendoza (Southern Central Andes) |
| title_short | Within plate seismicity analysis in the segment between the high Cordillera and the Precordillera of northern Mendoza (Southern Central Andes) |
| title_sort | within plate seismicity analysis in the segment between the high cordillera and the precordillera of northern mendoza southern central andes |
| topic | Crustal seismicity Seismogenic structures Frontal cordillera Blind thrusts Decollement |
| url | http://www.sciencedirect.com/science/article/pii/S167498471730109X |
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