Abstract
We report the discovery of massif-type anorthosites in the Andean basement of the Western Sierras Pampeanas of Argentina. U-Pb zircon dating (by sensitive high-resolution ion microprobe) of a cogenetic gabbronorite dyke yields ages of 1070 ± 41 Ma for igneous emplacement and 431 ± 40 Ma for metamorphism. These anorthosites are petrologically and geochemically comparable with those of the Grenville province of Laurentia. Palaeogeographical reconstructions of Rodinia at 1.0-1.1 Ga suggest that the Sierras Pampeanas anorthosites were part of a large anorthosite province in the late Mesoproterozoic.
Original language | English |
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Pages (from-to) | 9-12 |
Number of pages | 4 |
Journal | Journal of the Geological Society |
Volume | 162 |
Issue number | 1 |
DOIs | |
Publication status | Published - Jan 2005 |