A violet, coarse-grained, porphyritic quartz syenite , which makes up large parts of the pluton, was collected for dating.
The province is also endowed with other non-traditional minerals including nickel, feldspar, emerald, limestone, granite, amethyst, sodalite and syenite .
The selective removal of these minerals resulted in a change of the composition of the magma to one near that of the rock syenite .
Originally, the syenite was barged, until about 1949 when it was hauled by truck 24 miles to the CNR at Lakefield, which distance was only slightly farther than the CPR had to build.
The southern Zomba area consists mainly of syenite surrounded by a periphery of alkaline granite.
Other basaltic units and syenitic intrusions with ages 0.56 to 0.55 Ga are widely distributed.
Of far less importance are occurrences in gneisses and amphibolites, in small plutons derived from syenitic and gabbroic magmas, and in certain contact-metamorphic rocks.
In the central part of the intrusion, some small granitic aplite dykes intrude the syenitic rocks.
Several pools of syenitic magma were separated from the main body of the melt.
During the early Gardar period, around 1350 Ma, basaltic lavas were erupted and syenitic plutons were emplaced.