Zircon Behaviour during Low-temperature Metamorphism

Hafnium isotope homogenization during metamorphic zircon growth in amphibolite-facies rocks: Examples from the Shackleton Range (Antarctica)

“…That zircon growth can take place under such conditions has been shown by numerous field-based studies. It has been reported from amphibolite-facies rocks formed at 500°C/ 7 kbar (Dempster et al, 2008a), from low-grade metamorphic rocks formed at 250-400°C (Dempster et al, 2004;Fraser et al, 2004;Rasmussen, 2005;Hay and Dempster, 2009), and even from hydrothermal settings (Rubin et al, 1989;Hoskin, 2005).…”

Geochemistry of magmatic and hydrothermal zircon from the highly evolved Baerzhe alkaline granite: implications for Zr–REE–Nb mineralization

“…The high LREE concentrations of this type of zircon were not attributed to the theoretical partition coefficients of LREE between zircon and melt (Thomas et al 2002;Hanchar and Westrenen 2007), instead they are considered to be the result of LREE-rich inclusions in zircon or dramatically different behavior of LREE in highly evolved magmatic systems (Bakker and Elburg 2006). Generally, zircon from highly evolved granitic rocks is commonly porous and may contain U, Th, Nb, and Tarich inclusions when the host rocks experienced mineralization or alteration (Thomas et al 2003;Tomaschek et al 2003;Geisler et al 2007;Martin et al 2008;Hay and Dempster 2009;Van Lichtervelde et al 2009). However, the time-resolved LA-ICPMS spectra and element distribution maps (Electronic Supplementary Material Fig.…”

Detrital zircon without detritus: a result of 496-Ma-old fluid–rock interaction during the gold-lode formation of Passagem, Minas Gerais, Brazil

“…Xenotime forms across a range of metamorphic conditions (Heinrich et al, 1997;Pyle et al, 2001), and also occurs as an authigenic and detrital mineral in sedimentary rocks (Cabella et al, 2001;Cabral et al, 2012a;Suzuki and Adachi, 1991). Furthermore, zircon and xenotime can be partially altered, or even completely dissolved, during subsequent fluid-rock interaction, and newly re-precipitated under metamorphic conditions between 250°and 650°C (Dempster et al, 2004;Hay and Dempster, 2009;Rasmussen, 2005;Wilke et al, 2012;Zeh et al, 2010). Alteration, either related to leaching of metamict zircon domains, local recrystallisation, or coupled dissolution-reprecipitation processes, can lead to partial or total loss of radiogenic Pb from local domains or from whole grains in a wide range of geological settings (Geisler et al, 2001;Gerdes and Zeh, 2009;Hay and Dempster, 2009;Krogh and Davis, 1975;Mezger and Krogstad, 1997;Pidgeon, 1992;Vavra et al, 1999;Zeh et al, 2010).…”