Geochemical evolution of the Juan Fernandez Islands, SE Pacific
- 1 November 1987
- journal article
- Published by Geological Society of London in Journal of the Geological Society
- Vol. 144 (6) , 933-944
- https://doi.org/10.1144/gsjgs.144.6.0933
Abstract
The two main islands of the Juan Fernandez group, some 180 km apart are intra-plate volcanoes related to a single hot spot. K-Ar determinations suggest an age difference of c. 3 Ma which is in accord with a spreading rate of c. 6 cm a −1 in this part of the Nazca plate. The younger island of Alexander Selkirk is a relatively recent volcano (86 Sr/ 87 Sr ratios are fairly uniform ( c. 0.7035) in all the rock types but 143 Nd/ 144 Nd ratios are more variable, attaining their lowest values in some of the basanites. Trace element and isotopic data suggest remelting of source regions modified by migration of small degree partial melts over a long period.This publication has 22 references indexed in Scilit:
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