Bulletin of the Geological Society of Malaysia, Volume 8, Dec, 1977, pp. 117 – 120
Jabatan Geologi Universiti Malaya, Kuala Lumpur.
Abstract: Some pegmatite dykes in the Gunung Jerai granite at Merbok, Kedah have been found to be sheared and displaced. The shear zones, however, have been annealed by the granite which indicate that the dykes are synplutonic and therefore coeval with the granite. At the same outcrop a few of the pegmatite dykes have swollen parts with circular to elliptical cross-sections. These bulbous parts are probably formed by upwelling of pegmatitic materials into a still viscous granite host.
The recognition that the granite and pegmatite are coeval may help in the interpretation of geochronological data on the granite and pegmatite presented by Bignell (1972).