%0 Journal Article
%A Castiñeiras García, Pedro
%A Navidad Fernández De La Cruz, Marina
%A Casas Tuset, Josep María
%A Liesa Torre Marín, Montserrat
%A Carreras, Jordi
%T Petrogenesis of Ordovician Magmatism in the Pyrenees (Albera andCanigó Massifs) Determined on the Basis of Zircon Minorand Trace Element Composition
%D 2011
%@ 0022-1376
%U https://hdl.handle.net/20.500.14352/42553
%X Zircon composition (U, Th, rare earth elements, and Hf) was tested as a tracer of petrogenetic processes in a set ofmetaigneous rocks from two pre-Ordovician massifs in the Pyrenees, Canigo´ and Albera. Two groups were differentiatedafter analyzing a number of elements in zircon: (1) Casemı´ gneiss and Marialles amphibolite and (2) subvolcanicmetaporphyries and Cadı´ and Sureda orthogneisses. Casemı´ gneiss and Marialles amphibolite from the Canigo´massif have high Th, Th/U, and Ce/Sm and low Yb/Gd and U/Ce that define linear trends in most of the plots used.The anomalous trend of the data in the Th/U-versus-Hf plot suggests mantle involvement in the origin of these rocksand the participation of fractional crystallization during their evolution. Zircon of the metaporphyries and the Cadı´and Sureda orthogneisses exhibit similar characteristics despite a difference in age. Zircon has low Th, Th/U, Ce/Sm, and and high Yb/Gd and U/Ce, suggesting that this mineral grew in a melt formed by anatexis of a ∗ Eu/Eucontinental crust, with stable plagioclase. These petrogenetic data are consistent with the previously studied wholerockgeochemistry and Sr-Nd isotopes and confirmthe use of zircon as a marker of petrogenetic processes in preferenceto a lithological tracer.
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