Villaseca González, Carlos and Orejana García, David and Paterson, Bruce A. and Billstrom, Kjell and Pérez-Soba Aguilar, Cecilia (2007) Metaluminous pyroxene-bearing granulite xenoliths from the lower continental crust in central Spain: their role in the genesis of Hercynian I-type granites. European journal of mineralogy, 19 . pp. 463-477. ISSN 0935-1221
Official URL: http://www.schweizerbart.de/journals/ejm
Basic and intermediate meta-igneous xenoliths are very scarce within the granulite population transported by the Permian alkaline lamprophyric dyke swarmof the Spanish Central System(SCS). These xenoliths aremetaluminous pyroxene-bearing charnockites (sensu lato). They show LREE-poor plagioclase and orthopyroxene-clinopyroxene. Crystallization conditions were estimated at about 850 to 1000 ◦C and 9 to 11 kbar, a slightly higher range than that estimated for the associated peraluminous granulites, but indicating derivation from the lowermost crust. Whole-rock geochemistry suggests that the charnockite samples are not a cogenetic suite. The more basic varieties have affinities with cumulates from previous calc-alkaline underplated protoliths, whereas intermediate charnockites have a restitic origin. The similarity in Sr-Nd-Pb isotopic signatures between these restitic charnockites and some SCS I-type granites suggests a genetic relationship. This study, including Pb isotopic data from the whole granulite xenolith suite, reinforces the lower-crustal derivation of the SCS Hercynian granitic batholith.
|Uncontrolled Keywords:||Granulite xenoliths, Pyroxene mineral chemistry, Hercynian granites, Igneous petrology, Lower crust, Central Spain|
|Subjects:||Sciences > Geology > Petrology|
|Deposited On:||11 Mar 2011 11:42|
|Last Modified:||26 Nov 2012 10:10|
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