Pb-isotope data for feldspar separates are plotted on Pb-Pb diagrams and compared with potential source regions for the magmas. All fall above the MORB field and suggest an enriched mantle source similar to that reported for Quaternary ores and igneous rocks in central Chile. Samples from the Arequipa segment show a marked displacement towards low 206Pb/204Pb values reflecting contamination by Precambrian crustal rocks. This is not the case in the Lima segment where the most evolved rocks are contaminated by more radiogenic Pb.-R.J.P.
|Original language||English (US)|
|Number of pages||4|
|Journal||Magmatism at a Plate Edge: the Peruvian Andes|
|State||Published - 1985|
Bibliographical noteCited By :5
Export Date: 3 November 2016