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Monzogranites (MGr) are biotite granite rocks that are considered to be the final fractionation product of magma. Monzogranites are characteristically felsic (SiO2 > 73%, and FeO + MgO + TiO2 < 2.4), weakly peraluminous (Al2O3/ (CaO + Na2O + K2O) = 0.98–1.11), and contain ilmenite, sphene, apatite and zircon as accessory minerals. Although the compositional range of the monzogranites is small, it defines a differentiation trend that is essentially controlled by biotite and plagioclase fractionation. (Fagiono, 2002). Monzogranites can be divided into two groups (magnesio-potassic monzogranite and ferro-potassic monzogranite) and are further categorized into rock types based on their macroscopic characteristics, melt characteristics, specific features, available isotopic data, and the locality in which they are found. ==Monzogranite rock types== MGr type I: Muscovite-biotite-metagranite. Small and equal grained, greyish-brown, yellow altered K-fsp (Saladillo, S. Chepes). MGr type II: Muscovite-metagranite. Medium grained, porphyric, pink K-fsp, with "schollen", whitish-pink (with "Schollen"). MGr type III: Schollen-metagranite. Medium and equal grained, large and many "schollen", whitish-grey, only biotite (Tuaní, S. Chepes and S. Ulapes south). MGr type IV: Biotite-metagranite. Medium to large, porphyric or equal grained pink K-fsp, reddish quartz (Chimenea, S. Chepes). MGr type V: Metagranite. Medium and equal grained reddish K-fsp whitish (El Abra, S. Ulapes). MGr type V aplite: Metagranite, aplite dikes and layers. Pink small and equal grained, whitish K-fdsp, grey quartz, pink-white (S. Ulapes north). 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「monzogranite」の詳細全文を読む スポンサード リンク
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