Geochronological and geochemical investigations on plutonic rocks from the complex of Puerto Vallarta, Sierra Madre del Sur
Within the Sierra Madre del Sur nine intrusive complexes, varying in composition from trondjemitic to granitic, have been identified by Negendank et al. (1985). The age of the complexes, based on stratigraphic and to a limited extent on radiometric data, ranges from Jurassic to Cenozoic. In order to...
| Autores: | , , , , , |
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| Tipo de recurso: | artículo |
| Estado: | Versión publicada |
| Fecha de publicación: | 1988 |
| País: | México |
| Institución: | UNIVERSIDAD NACIONAL AUTÓNOMA DE MÉXICO |
| Repositorio: | Geofísica Internacional |
| Idioma: | español |
| OAI Identifier: | oai:revistagi.geofisica.unam.mx:article/1168 |
| Acceso en línea: | http://revistagi.geofisica.unam.mx/index.php/RGI/article/view/1168 |
| Access Level: | acceso abierto |
| Palabra clave: | Geocronología geoquímica rocas plutónicas Puerto Vallarta Sierra Madre del Sur México Geochronology geochemistry plutonic rocks |
| Sumario: | Within the Sierra Madre del Sur nine intrusive complexes, varying in composition from trondjemitic to granitic, have been identified by Negendank et al. (1985). The age of the complexes, based on stratigraphic and to a limited extent on radiometric data, ranges from Jurassic to Cenozoic. In order to determine the age of intrusion and cooling of the granitoids of the complex of Puerto Vallarta and to shed some light on the origin of the respective melts Rb-Sr and K-Ar whole-rock and mineral measurements have been carried out. The results obtained are:- The intrusion age of the granitoid is limited between 97 ± 3 Ma and 88 ± 2 Ma, the biotite cooling age is 83± 3 Ma for the Rb-Sr system. The hornblende cooling age is 86 ± 2 Ma for the K-Ar system.- the cooling rate of the complex of Puerto Vallarta in the interval from about 100 Ma to about 80 Ma is approximately 35°C per 1 Ma.- the granitoids have 87Sr/86Sr-initial ratios between 0. 704 and 0. 706, which indicate a possible mantle origin.- basicfenoliths and the surrounding granitoids are derived from different sources. |
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