Contribution
Moldanubian granulites: Source material and petrogenetic considerations
Fiala, J.; Matějovská, O.; Vaňková, V.
Neues Jahrbuch für Mineralogie - Abhandlungen Band 157 Heft 2 (1987), p. 133 - 165
65 références bibliographiques
publié: Sep 2, 1987
DOI: 10.1127/njma/157/1987/133
ArtNo. ESP154015702003, Prix: 29.00 €
Abstract
The study presents geochemical characteristics (contents of Th, U, K, Rb, Sr, Ba, Y, Zr, V, Cr, Ni and major oxides) of the Moldanubian granulites obtained on the basis of 106 samples. The studied granulites form three groups representing various pre-granulitic source materials: acid pyroxene-free granulites (group A) correspond to meta-igneous rocks of granite/rhyolite composition; subacid to intermediate pyroxene-bearing granulites (group B1) represent metamorphosed members of a “normal” calc-alkaline igneous rock series; subacid pyroxene-free granulites (group B2) are probably metamorphosed arenitic sediments. In comparison to upper crustal equivalents the Moldanubian granulites are not depleted in K and Rb, which does not point to a substantial participation of syngranulitic anatexis in the process of metamorphism. The observed low Th, U, Zr, and Sr contents may be explained by their selective removal into a fluid phase during granulite metamorphism.
Mots-clefs
Granulites • geochemistry • petrography • major element analyses • trace element analyses • Th • U • K • heat production • metamorphism • Bohemian Massif • Moldanubicum • genesis • source material • geotectonic setting