Fluid-induced magmatic and post-magmatic zircon and monazite patterns in granitoid pluton and related rhyolitic bodies


Fluid-induced magmatic and post-magmatic zircon and monazite patterns in granitoid pluton and related rhyolitic bodies

Lisowiec, K.; Bartosz, B.; Słaby, E.; Renno, A. D.; Götze, J.

Zircon and monazite from the Stolpen granite and related rhyolitic dyke show magmatic as well as post-magmatic textures. The magmatic textures are overprinted by post-magmatic fluid interaction which is indicated by elevated contents of Y, P, Th, and U in altered zircon domains. This can be observed both in the granite and rhyolite; however these processes were less intensive in the rhyolite. Patchy zoning in primary monazite from the granite also suggests fluid-induced alterations. High Ca, Pb, and Si contents and depletion in Th, as well as porous, spongy textures in monazite from the rhyolite are results of fluid-induced alterations that caused also crystallization of cheralite. Zircon and monazite from the granite are accompanied by fluorite, Y-rich and Nb-rich minerals. The alteration of primary, magmatic accessory minerals and formation of secondary minerals is interpreted as related to magmatic fluids, which origin cannot be defined precisely on the base of the present data, however their composition suggests some mantle contribution. The presence of fluorine and CO2 which promoted the transport of some HFSE and LILE accounts for their enrichment in the accessory minerals. Fluids that affected the accessory minerals from the rhyolite show different features (silica- and Ca-enrichment) and most probably came from another source

Keywords: Zircon; monazite; Stolpen granite; electron microprobe

Permalink: https://www.hzdr.de/publications/Publ-18133
Publ.-Id: 18133