Mineral chemistry of ultramafic rocks associated with the Asaji metamorphic rocks, eastern Kyushu

mineral chemistry of garnet in pegmatite and metamorphic rocks in the hamedan area

introduction the area of this study is located near hamadan within the sanandaj - sirjan tectonic zone. in the hamadan area, consisting mainly of mesozoic plutonic and metamorphic rocks, aplites and pegmatites locally contain garnets.(baharifar et al., 2004, amidi and majidi, 1977; torkian, 1995. garnet-bearing schists and hornfelses in the area are products of regional metamorphism shown by sl...

Mineral chemistry and thermobarometry of Eocene Alkaline volcanic rocks in the Southwest of Germi, NW Iran

Petrography and chemistry of minerals showing that Eocene alkaline volcanic rocks in southwestern of Germi (Talesh zone, NW Iran) mostly have basaltic composition. Mineralogically these rocks are composed of diopsidic clinopyroxene and labradoritic plagioclase phenocrysts. The microlithic and glassy groundmass composed of sanidine, clinopyroxene, biotite, pargasitic amphibole and magnetite asso...

Mineral Chemistry of Chlorite Replacing Biotite from Granitic Rocks of the Canadian Appalachians

Chlorite flakes, as a product of alteration of biotite, the dominant ferromagnesian mineral in the Paleozoic granitic rocks of the Canadian Appalachians, have been analyzed by electron microprobe for major elements and by 57Fe M?ssbauer spectroscopy for the coordination and oxidation state of Fe. Comparison of M?ssbauer Fe3+/Fe ratios obtained from chlorite and its host biotite indicates that c...

Groundwater in Sedimentary, Metamorphic and Volcanic Rocks

Unraveling alteration histories in serpentinites and associated ultramafic rocks with magnetite (U-Th)/He geochronology

Serpentinization is a widespread process that affects large-scale geodynamic processes along plate boundaries, including continental breakup, seafloor spreading, and subduction. Documenting the timing of serpentinization is critical for our understanding of these processes, but direct dating of serpentinites has been challenging or impossible. We present the first application of magnetite (U-Th...