40Ar/39Ar ages from blueschists of the Jambaló region, Central Cordillera of Colombia
This paper presents the first argon dating of blueschists from the Jambaló area (Cauca Department) in the Central Cordillera of the Colombian Andes. Step-heating 40Ar/39Ar spectra were obtained for mica from several lenses of blueschists including greenschist facies rocks. The blueschists are mainly...
| Authors: | ; ; ; |
|---|---|
| Format: | Article |
| Publication date: | 2011 |
| Country: | España |
| Institution: | Universitat Autònoma de Barcelona |
| Repository: | Dipòsit Digital de Documents de la UAB |
| Language: | English |
| OAI Identifier: | oai:ddd.uab.cat:89014 |
| Online Access: | https://ddd.uab.cat/record/89014 https://dx.doi.org/urn:doi:10.1344/105.000001697 |
| Access Level: | Open access |
| Keyword: | Blueschists Colombian Andes Jambaló area 40Ar/39Ar geochronology |
| _version_ | 1878729119840075776 |
|---|---|
| author | Bustamante, Andrés |
| author2 | Juliani, Caetano Hall, C. M. Essene, E. J. |
| author2_role | author author author |
| author_browse | Bustamante, Andrés Essene, E. J. Hall, C. M. Juliani, Caetano |
| author_facet | Bustamante, Andrés Juliani, Caetano Hall, C. M. Essene, E. J. |
| author_role | author |
| collection | Dipòsit Digital de Documents de la UAB |
| description | This paper presents the first argon dating of blueschists from the Jambaló area (Cauca Department) in the Central Cordillera of the Colombian Andes. Step-heating 40Ar/39Ar spectra were obtained for mica from several lenses of blueschists including greenschist facies rocks. The blueschists are mainly constituted of preserved lenticular cores in strongly mylonitic rocks, which resulted from retrometamorphic processes that affected the high pressure rocks during their exhumation. The majority of 40Ar/39Ar data points to metamorphic ages close to 63±3Ma, but some ages are older than 71Ma. These Maastritchtian-Danian ages correspond to the timing of exhumation of the blueschists near metamorphic peak conditions, because the dated paragonite and phengite crystallized during development of the mylonitic foliation. The continuous exhumation of this blueschist belt between 71-63Ma reflects the flow on an accretionary system/subduction channel environment that was interrupted by the collision of an intra-oceanic arc with the continental margin. Regional geological correlations suggest that this arc-continent collision also took place in Ecuador. This collisional event, although synchronous with other arc-continent collisions in the Northern Andes, was apparently not related to the formation of the great Caribbean arc, but to an arc built in the southeastern margin of the Caribbean plate. |
| eu_rights_str_mv | openAccess |
| format | article |
| id | ES_01d48959cd6eaeaa46cebd4ec182401e |
| institution | Universitat Autònoma de Barcelona |
| instname_str | Universitat Autònoma de Barcelona |
| language | eng |
| network_acronym_str | ES |
| network_name_str | España |
| oai_identifier_str | oai:ddd.uab.cat:89014 |
| publishDate | 2011 |
| publishDateSort | 2011 |
| reponame_str | Dipòsit Digital de Documents de la UAB |
| spelling | 40Ar/39Ar ages from blueschists of the Jambaló region, Central Cordillera of Colombia implications on the styles of accretion in the Northern Andes Bustamante, Andrés Juliani, Caetano Hall, C. M. Essene, E. J. Blueschists Colombian Andes Jambaló area 40Ar/39Ar geochronology This paper presents the first argon dating of blueschists from the Jambaló area (Cauca Department) in the Central Cordillera of the Colombian Andes. Step-heating 40Ar/39Ar spectra were obtained for mica from several lenses of blueschists including greenschist facies rocks. The blueschists are mainly constituted of preserved lenticular cores in strongly mylonitic rocks, which resulted from retrometamorphic processes that affected the high pressure rocks during their exhumation. The majority of 40Ar/39Ar data points to metamorphic ages close to 63±3Ma, but some ages are older than 71Ma. These Maastritchtian-Danian ages correspond to the timing of exhumation of the blueschists near metamorphic peak conditions, because the dated paragonite and phengite crystallized during development of the mylonitic foliation. The continuous exhumation of this blueschist belt between 71-63Ma reflects the flow on an accretionary system/subduction channel environment that was interrupted by the collision of an intra-oceanic arc with the continental margin. Regional geological correlations suggest that this arc-continent collision also took place in Ecuador. This collisional event, although synchronous with other arc-continent collisions in the Northern Andes, was apparently not related to the formation of the great Caribbean arc, but to an arc built in the southeastern margin of the Caribbean plate. https://ddd.uab.cat/record/89014 https://dx.doi.org/urn:doi:10.1344/105.000001697 |
| spellingShingle | 40Ar/39Ar ages from blueschists of the Jambaló region, Central Cordillera of Colombia Bustamante, Andrés Blueschists Colombian Andes Jambaló area 40Ar/39Ar geochronology |
| title | 40Ar/39Ar ages from blueschists of the Jambaló region, Central Cordillera of Colombia |
| title_full | 40Ar/39Ar ages from blueschists of the Jambaló region, Central Cordillera of Colombia |
| title_fullStr | 40Ar/39Ar ages from blueschists of the Jambaló region, Central Cordillera of Colombia |
| title_full_unstemmed | 40Ar/39Ar ages from blueschists of the Jambaló region, Central Cordillera of Colombia |
| title_short | 40Ar/39Ar ages from blueschists of the Jambaló region, Central Cordillera of Colombia |
| title_sort | 40Ar/39Ar ages from blueschists of the Jambaló region, Central Cordillera of Colombia |
| topic | Blueschists Colombian Andes Jambaló area 40Ar/39Ar geochronology |
| topic_facet | Blueschists Colombian Andes Jambaló area 40Ar/39Ar geochronology |
| url | https://ddd.uab.cat/record/89014 https://dx.doi.org/urn:doi:10.1344/105.000001697 |