Resumen
Two metamorphic complexes of different lithology and structure occur in the coast ranges of central Chile. The Tanume metamorphic complex to the east belongs to a low P-T series of sillimanite-cordierite gneisses derived from a continental platform clastic sedimentary sequence and gives a whole-rock isochron age of 347 + or - 32 m.y. whereas the accreted Pichilemu complex to the west consists of stilpnomelane-bearing cherts, crossite-bearing metabasic rocks and siliceous metapelites, with an age of 311 + or - 10 m.y. Different provenance of the protoliths is indicated by the higher 87Sr/ 86Sr initial ratios of the Tanume rocks (0.7124 + or - 0.0007) relative to the Pichilemu rocks (0.7060 + or - 0.0005), which were more affected than the former by the main phase of deformation and metamorphism in the area.-R.A.H.
Idioma original | Inglés |
---|---|
Páginas (desde-hasta) | 877-884 |
Número de páginas | 8 |
Publicación | Journal of the Geological Society |
Volumen | 141 |
N.º | 5 |
Estado | Publicada - 1984 |
Áreas temáticas de ASJC Scopus
- Ciencias de la Tierra y Planetarias General
- Ciencias planetarias y de la Tierra (miscelánea)
- Geología
- Ciencias Ambientales General