ORIGINAL PAPER Alfons M. van den Kerkhof Æ Andreas Kronz Klaus Simon Æ Torsten Scherer Fluid-controlled quartz recovery in granulite as revealed by cathodoluminescence and trace element analysis (Bamble sector, Norway) Received: 15 March 2003 / Accepted: 18 September 2003 / Published online: 11 November 2003 Ó Springer-Verlag 2003 Abstract Dispersed quartz veinlets in Proterozoic end- erbitic charnockite from Tromøy, Bamble sector (south- ern Norway), with Ti-concentrations of mostly 80– 180 ppm, produce bright blue cathodoluminescence (CL), against contrasting micro-textures of secondary pure quartz with low CL intensity. The textures comprise grain boundary alteration, healed micro-fractures, pat- ches of secondary quartz, and euhedral quartz nuclei. The secondary quartz locally makes up 50% of the total quartz. Trace element analysis has been done by electron- probe micro-analysis (EPMA), laser-induced coupled plasma mass spectrometry (LA-ICPMS), and additional electron-paramagnetic resonance (EPR) spectroscopy. These studies testify systematic trace element reduction and extensive quartz recovery during retrograde meta- morphism. We assume healing of a part of the aqueous fluid inclusions during a late thermal event, possible cor- related with Paleozoic magmatic activity in the Oslo-Rift. During final cooling, aqueous fluids were largely re- trapped in patches of secondary quartz associated with healed fractures, whereas carbonic inclusions (without secondary quartz) may have survived retrograde meta- morphism. The variable but generally high salinity of fluid inclusions is assumed to be in part the result of quartz recovery by which ion concentrations were increased in the percentage range. Introduction The high sensitivity of cathodoluminescence (CL) for monitoring structural and chemical differences in quartz makes this technique highly powerful for revealing and mapping fluid-rock interaction processes. Quartz well preserves the structural information of the rock and forms a common host for fluid inclusions. During the last decades various CL studies have been applied to the study of micro-textures in quartz (Ramseyer and Mullis 2000; Go¨tze et al. 2001). In this way generations of quartz veins and fillings, such as in stockwork-type hydrothermal deposits, can be distinguished (e.g. Boiron et al. 1992; Winslow et al. 1994; Brinckmann et al. 2001). However, only a few CL studies deal with massive bar- ren metamorphic rocks. Inevitably, such studies are almost always restricted to secondary micro-textures, which form under retrograde conditions, a branch of metamorphic petrology, which has received less atten- tion. Contrary to mineral and fluid equilibria at the peak of metamorphism, the processes during disequilibria conditions at lower P and T are less well understood. The CL of quartz is caused by a variety of intrinsic and extrinsic defect structures with the latter principally related to the incorporation of trace elements and structural water. The defect structure inventory reflects the physico-chemical conditions during primary crys- tallization and during changes induced by metamor- phism, deformation and retrogression. Temperature changes, chemical gradients created during mineral reactions, and the interaction with aqueous fluids may result in a wide variety of micro-textures, which are visible in CL, but difficult or impossible to observe by any other imaging technique (Behr and Frentzel-Beyme 1987; Frentzel-Beyme 1989; Boiron et al. 1992; Krynauw et al. 1994; Holness and Watt 2001; Van den Kerkhof and Hein 2001). These textures show in part a close association with fluid inclusions. The reconstruction of the metamorphic evolution from fluid inclusion data requires accurate knowledge Contrib Mineral Petrol (2004) 146: 637–652 DOI 10.1007/s00410-003-0523-5 Editorial Responsibility: J. Touret A. M. van den Kerkhof (&) Æ A. Kronz Æ K. Simon Geowissenschaftliches Zentrum der Universita¨t Go¨ttingen (GZG), Goldschmidtstr. 1–3, 37077 Go¨ttingen, Germany E-mail: akerkho@gwdg.de T. Scherer Institut fu¨r Mineralogie, Philipp-Universita¨t Marburg, Hans-Meerwein-Str, 35032 Marburg, Germany Present address: T. Scherer Forschungszentrum Karlsruhe, Institut f. technische Chemie (ITC), Hermann-von-Helmholtzplatz 1, 76344 Eggenstein-Leopoldshafen, Germany