a particular feature of biotite grains from some of the canadian appalachian granitic rocks is the presence of lenses of ca-al silicates developed along cleavage planes. these from the more to less common are prehnite, pumpellyite and grandite garnet, an intermediate composition between andradite and grossular. rarely all three minerals can be observed together in one single biotite grain. micr...

A particular feature of biotite grains from some of the Canadian Appalachian granitic rocks is the presence of lenses of Ca-Al silicates developed along cleavage planes. These from the more to less common are prehnite, pumpellyite and grandite garnet, an intermediate composition between andradite and grossular. Rarely all three minerals can be observed together in one single biotite grain. Micr...

Semi-pelitic rocks ranging in grade from the prehnite–pumpellyite to the greenschist facies from southeastern Otago, New Zealand, have been investigated in order to evaluate the reactions leading to formation and breakdown of stilpnomelane. Detrital grains of mica and chlorite along with fine-grained authigenic illite and chlorite occur in lower-grade rocks with compactional fabric parallel to ...

Monazite-(Ce) and xenotime-(Y) were found in the metacherts (pumpellyite–actinolite-facies conditions: 3 ≤ P ≤ 4 kbars and 300 ≤ T ≤ 350°C) of the Monte Figogna Unit, Sestri–Voltaggio Zone, Liguria, in Italy, as scattered submillimetric grains in pelitic beds and as euhedral crystals in both millimeter-thick quartz veins and open fissures. Their composition is comparable to those of known occur...

The Kongsberg and Bamble lithotectonic domains of SE-Norway are known as classical Precambrian high-grade metamorphic terrains. area has undergone extensive metasomatism with formation albitites scapolite-rich rocks numbers previously economically important deposits including the Silver Modum Cobalt mines. We demonstrate here that central part domain (Kragerø area) locally developed low-grade m...