Author | dc.contributor.author | Massonne, Hans-Joachim | |
Author | dc.contributor.author | Calderón, Mauricio | es_CL |
Admission date | dc.date.accessioned | 2010-01-27T18:22:44Z | |
Available date | dc.date.available | 2010-01-27T18:22:44Z | |
Publication date | dc.date.issued | 2008-07 | |
Cita de ítem | dc.identifier.citation | Revista Geológica de Chile 35 (2): 215-231, 2008 | en_US |
Identifier | dc.identifier.issn | 0716-0208 | |
Identifier | dc.identifier.uri | https://repositorio.uchile.cl/handle/2250/125254 | |
Abstract | dc.description.abstract | In the Guarguaraz Complex of the Argentine Frontal Cordillera (latitude 33.3°S) serpentinite lenses,
metabasites, and garnet-bearing metasedimentary rocks occur. The corresponding Devonian metamorphic event was
assigned to the formation of an accretionary wedge by previous authors. We have tested this hypothesis by investigating
the metamorphic evolution of a pelite from this complex. Garnet in this rock shows a well evolved prograde zoning.
Potassic white mica with Si contents between 3.38 (core) and 3.12 (rim) per formula unit, biotite, quartz and plagioclase,
which have formed late blasts at the expense of amphibole, coexist with this phase. On the basis of P-T pseudosections
and water-absent equilibria, we have estimated the subsequent P-T path for the studied metapelite. The garnet core
formed at about 8 kbar and 470-500°C. After nearly isothermal burial to 45 km (13.5 kbar) where Si-rich phengites
grew, temperatures increased followed by exhumation and an overprint stage at 8 kbar and 565°C. This P-T path is not
compatible with the idea of an accretionary wedge complex. It is more likely that the high-pressure conditions were
attained by thickening of continental crust when the hypothetical Chilenia terrane collided with the continental margin
of western Gondwana in Devonian times. | en_US |
Patrocinador | dc.description.sponsorship | The stay of HJM in South America was fi nancially
supported by a BMBF-CONICYT program (CHL
02/012). | en_US |
Lenguage | dc.language.iso | en | en_US |
Publisher | dc.publisher | SERVICIO NACIONAL GEOLOGIA MINERVA | en_US |
Keywords | dc.subject | Metapelite | en_US |
Título | dc.title | P-T evolution of metapelites from the Guarguaraz Complex, Argentina: evidence for Devonian crustal thickening close to the western Gondwana margin | en_US |
Document type | dc.type | Artículo de revista | |