%0 Journal Article
%A Villaseca González, Carlos
%A Orejana García, David
%T Rutilos ricos en Zr incluidos en granates de xenolitos granulíticosde la corteza inferior del Sistema Central Español: implicacionesgeodinámicas
%D 2008
%@ 0213-683X
%U https://hdl.handle.net/20.500.14352/49608
%X Two petrographic types of rutile are observed in the peraluminous felsic meta-igneous granulites, the mostcommon type of the lower crustal xenolith suite of the Spanish Central System (SCS). Rutile-1 (Rt-1)corresponds to small crystals (mainly < 80 mm) only preserved as micro-inclusions within garnet, whereasrutile-2 (Rt-2) is commonly found as big idiomorfic crystals forming the granulite granoblastic matrix.Chemical analyses by EMP show a higher Zr content in Rt-1 (up to 7800 ppm) than in Rt-2 (up to 5200ppm) of the same granulite. Applying Zr-in-rutile thermometry, Rt-1 gives 50-60 ºC higher for rutilecrystallization (950-1015 ºC) when compared to Rt-2 thermometry (940-955 ºC). These ultra-hightemperatures (UHT) are likely attained at Moho depths without external heat sources (e.g. mantle input)as supported by the high heat production estimated for the crustal section of the SCS. The granulitegranitepetrogenetic link suggests that these HT-UHT granulites were generated by intra-crustal reworkingduring Hercynian continental thickening.
%~