A note on lower jurassic magmatism in the coastal cordillera of atacama, Chile
By: Naranjo, J.A
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Contributor(s): Puig, A | Suárez, M.
Material type: 
ArticleDescription: 699-702pp ; Illustration.Subject(s): Lower jurassic magmatism - Atacama - Chile | Petrology - South Africa | Lower jurassic Plutonism
In:
Geological magazine : Vol. 123 Iss. 1-6 Year. 1986Summary: Radiometric dates on specimens of plutons of the Coastal Cordillera of Atacama span the period 300–110 Ma. A group of dates cluster around 190 Ma and evidence is presented which strongly suggests that they represent near crystallization ages. The geographic distribution of these plutons, adjacent to Liassic tuffs and lavas (Pan de Azúcar and Posada de los Hidalgo formations), suggests a genetic relationship between them, and that the plutons were the roots of the Lower Jurassic volcanic chain. The location of these granitoids to the west of the Liassic volcanic rocks, favours a previous idea that the Liassic basin extended eastwards as a back-arc or intra-arc basin. The host rocks to the Lower Jurassic plutons include Palaeozoic granitoids and metasedimentary rocks, indicating that the volcanic chain was founded on continental crust. The distance from the Liassic plutons to the present-day trench is less than 100 km, which indicates the possibility that part of the arc-trench system of that time is missing.
| Item type | Current location | Collection | Call number | Status | Date due | Barcode |
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Article
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Library and Information Centre Periodical Section | Bound Journal Collection | Not for loan | 002533_145 | ||
Serials/Scientific Journal
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Library and Information Centre Periodical Section | Bound Journal Collection | 550 GEO (Browse shelf) | Available | 002533 |
Radiometric dates on specimens of plutons of the Coastal Cordillera of Atacama span the period 300–110 Ma. A group of dates cluster around 190 Ma and evidence is presented which strongly suggests that they represent near crystallization ages. The geographic distribution of these plutons, adjacent to Liassic tuffs and lavas (Pan de Azúcar and Posada de los Hidalgo formations), suggests a genetic relationship between them, and that the plutons were the roots of the Lower Jurassic volcanic chain. The location of these granitoids to the west of the Liassic volcanic rocks, favours a previous idea that the Liassic basin extended eastwards as a back-arc or intra-arc basin. The host rocks to the Lower Jurassic plutons include Palaeozoic granitoids and metasedimentary rocks, indicating that the volcanic chain was founded on continental crust. The distance from the Liassic plutons to the present-day trench is less than 100 km, which indicates the possibility that part of the arc-trench system of that time is missing.
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