Bulletin of the Geological Society of Malaysia, Volume 45, May 2002, pp. 224 – 230
Department of Geology, University of Malaya, 50603 Kuala Lumpur, Malaysia
Abstract: This paper describes some of the important petrographic characteristics of the mafic microgranular enclaves from the Eastern Belt granite of Peninsular Malaysia as well as their chemical relationship. The enclaves are invariably darker coloured and finer grained than the enclosing granitic rocks. They usually have sharp contact with the granitic host. Occurrence of the acicular apatite in the enclave indicates that the crystals are·quenched, probably formed when a globule of relatively mafic (enclave) magma comes into contact with cooler granitic magma (granitic host). Occurrence of the quartz-hornblende ocellar reflected hybridism of the two magmas. The variable geochemical trends in the enclave and their host rocks is probably related to the variable degrees of diffusive exchange between the enclave and their host rock magmas during slow cooling.