Journal of

GEOsciences

  (Formerly Journal of the Czech Geological Society)

Original Paper

Zachovalová, Jaromír Leichmann, Švancara

Žulová Batholith: A post-orogenic, fractionated ilmenite - Allanite I-type granite

Journal of the Czech Geological Society, volume 47 (2002), issue 1-2, 35 - 44

DOI: http://doi.org/10.3190/JCGS.849

The major-element chemistry as well as mineralogy indicate that Žulová Batholith could be classified as a fractionated I-type granite. The interpretation of gravity data indicates a fair homogeneity of the batholith. The less fractionated amphibole - biotite tonalites and granodiorites form enclaves with remarkable cumulate textures. They are enriched in HFSE and REE as a consequence of crystal accumulation of allanite, apatite, ilmenite and titanite, their feldspar shows a rather simple internal fabric in CL. The more fractionated biotite granites constitute substantial part of the batholith. The enrichment in LILE and depletion in HFSE and REE corresponds to higher content of K-feldspar and lower amount of accessory phases. Feldspars exhibit complex internal fabric in CL, indicating a major role for feldspar fractionation in the evolution of the batholith, as does the pronounced negative Eu anomaly and higher K/Ba ratio. The emplacement of the batholith was probably related to the Westphalian extensional tectonics. The Upper Carboniferous and lower Permian extension seems to have been generally of great importance for magmatic history of the eastern margin of Bohemian Massif, as manifested in the Boskovice Furrow, where the extensional tectonics connected with magmatic activity could be also documented.