Skip to main content
Fig. 6 | Swiss Journal of Geosciences

Fig. 6

From: Eclogitic metamorphism in the Alpine far-west: petrological constraints on the Banchetta-Rognosa tectonic unit (Val Troncea, Western Alps)

Fig. 6

Representative microstructures of the samples used for P–T modeling. a, b AC44. a Polygonal arc of chloritoid crystals, with S2 axial plane schistosity defined by phengite + glaucophane (PPL); b S1 microlithon with chloritoid crystals (Cld1) wrapped by S2 main foliation, defined by a second generation chloritoid (Cld2) + glaucophane + phengite. Chlorite replaces both chloritoid and glaucophane (PPL). c, d Sample VT8. c Boundary between matrix (lower part) and a lens-like domain (upper part), with relic S1 foliation almost completely replaced by white mica (= Wm) + chlorite + albite S2 axial plane schistosity (PPL); d Intergrowth of white mica and paragonite close to syn-D2 chloritoid crystals (Cld2), almost completely replacing syn-D1 chloritoid (Cld1); note on the right a large rutile crystal (BSE). eg Sample AC74. e Syn-D1 chloritoid crystals (Cld1) preserved in a microlithon wrapped by S2 main foliation, defined by a second generation of chloritoid (Cld2) + phengite + quartz. Note the micro-scale expression of D3 tectono-metamorphic event, characterized by gentle folding (PPL); f Partially retrogressed syn-D1 jadeite crystal, wrapped by the main foliation and locally replaced by albite + quartz intergrowth (PPL). The inset shows a detail of jadeite + quartz intergrowth (BSE); g Schematic cartoon showing the most characteristic micro-structures and relationships of the three main tectono-metamorphic events

Back to article page