Bulletin of the Geological Society of Malaysia, Volume 44, July 2000, pp. 117 – 124
Geology Department, University of Malaya, 50603 Kuala Lumpur
Abstract: This work presents new muscovite analyses from the Kuala Lumpur granite. The muscovites have been analysed from three different samples namely equigranular normal biotite-muscovite granite (normal facies – NBMG), deformed muscovite granite (deformed facies – DBMG) and porphyritic biotite-muscovite granite (contact facies – PBMG). On textural ground the muscovite can be divided into primary and secondary. The primary muscovite is characterised by subhedral to euhedral shape, large grain size and occurs as muscovite clot. Those of secondary origin occurs mainly as replacement of feldspar. The primary muscovite is characterised by high Ti, AI, Mg/Mg + Fe and Ba and low Na and P. The major difference of the muscovites from the three samples are the TiO2 contents. Thus, muscovites from the PBMG have the lowest TiO2 content (mean: 0.04%) and those from the NBMG have the highest TiO2 content (mean: 0.53%). AIl muscovites sample from the DBMG and PBMG plot in the secondary muscovite field of Miller et al. (1981) those from the NBMG plot in the primary muscovite field. Muscovites from the NBMG have high BaO and low P2O5 contents compared to those from the other two samples. The decreasing Na content in muscovite from the DBMG may be related to the decrease of formation temperature and the variation of Fe, Mg and AI with Si can be related to solid solution between the end members muscovite and caledonite.
https://doi.org/10.7186/bgsm44200015
