Bulletin of the Geological Society of Malaysia, Volume 44, July 2000, pp. 139 – 150
Department of Geology, University of Malaya, 50603 Kuala Lumpur
Abstract: The Bukit Mertajam-Kulim granite consists of three units, namely, the Mertajam, Bongsu and Panchor granites which were emplaced in a relatively short time span between 180 to 224 Ma. All three units consists of rocks ranging from equigranular fine to coarse grained syeno- to monzogranite with subordinate porphyritic types. The essential minerals in all granites are K-feldspar, plagioclase, quartz, biotite, muscovite, tourmaline, apatite, zircon, garnet and opaque phases. The range of SiO2 for each of the units overlap: Mertajam granite (71.49-74.73%), Bongsu granite (73.59-76.27%) and Panchor granite (70.21-73.91%). The rocks in many aspects, are comparable to the ‘S‘ type granites from the Lachlan Fold Belt of Australia. The mineral mixes predicted in the major elements modeling confirm the dominance of plagioclase and K-feldspar in the fractionation process.