Title
Geodynamic evolution of the early Paleozoic Western Gondwana margin 14°-17°S reflected by the detritus of the Devonian and Ordovician basins of southern Peru and northern Bolivia
Date Issued
01 January 2010
Access level
metadata only access
Resource Type
journal article
Author(s)
Reimann C.R.
Bahlburg H.
Kooijman E.
Berndt J.
Gerdes A.
López S.
Publisher(s)
Elsevier Inc.
Abstract
We present results of a combined study of in situ U-Pb and Lu-Hf analyses on detrital zircons of Ordovician to Devonian sandstone successions of the Eastern Cordillera of Peru and Bolivia, as well as of the Altiplano and Coastal Cordillera of Peru (14°-17°S). We use our data to constrain the provenance and tectonic evolution of this part of the Gondwana margin in the early Paleozoic. The zircon-age composition is very variable in the different locations. Sandstones of the Eastern Cordillera have a dominant input of Brazilian-age zircons (0.7-0.5Ga) with two prominent peaks at around 0.52- 0.58Ga and 0.61-0.67Ga. A prevailing eastern source (Brazilian Shield, Amazonian Craton) is inferred. In contrast, sandstones from the Coastal Cordillera and Altiplano have major inputs of Famatinian (0.5-0.4Ga), Grenvillian (1.2-0.9Ga) and occasionally zircons of 1.85-1.75Ga crystallisation ages. Here, a dominant provenance from the Arequipa Massif is likely. Zircons preserving a juvenile component with εHf(t) values range from about +12 to +6 are limited to crystallisation ages between 1.45 and 1.0 Ga. All younger grains have lower εHf(t) values consistent with recycling of old crust without juvenile additions during the Neoproterozoic. Brazilian-age zircons of an Amazonian craton provenance and Famatinian-age zircons of an Arequipa Massif provenance have similar Hf model ages suggesting their derivation from the same evolved crust. © 2010 International Association for Gondwana Research.
Start page
370
End page
384
Volume
18
Issue
March 2
Language
English
OCDE Knowledge area
Geología
Scopus EID
2-s2.0-77954959194
Source
Gondwana Research
ISSN of the container
1342937X
Sponsor(s)
This work was supported by the German Research Foundation ( grant Ba-1011/27-1+4 ). C. Augustsson and N.S Keller are thanked for fruitful discussions and valuable comments on earlier versions of this contribution. We also thank P. Isaacson, University of Idaho, USA, for the determination of the Devonian brachiopods. Valuable comments by anonymous reviewers led to many improvements in the paper.
Sources of information: Directorio de Producción Científica Scopus