2 The story of Granite and Bega Cheese - Sapphire Coast

took place landwards of the plate boundary, the so-called Palaeo-Pacific oceanic
trench, with the oceanic plate sliding under (subducting beneath) the thick
Gondwanan continental crust. As the oceanic plate sank, under increasing
temperature and pressure and reactions with water saturated sediment, the rock
materials melted and then rose like huge hot air balloons up through the crust (the
plutons).
If such molten rock, or magma, reaches the surface it can form explosive andesite
volcanoes that are common today around the Pacific Ocean ‘ring of fire’ (actually a
series of tectonic plate boundaries). If the magma cools below the surface, it forms
granite – a generic term that covers a wide range of silica rich igneous rocks.
Variations in chemical composition give granites their diverse colours and textures
that distinguish one pluton from another. These variations make a diversity of
building stones. Examples of this diversity are:
The Bega granites are similar in appearance to number 3, with dominance of the
white form of feldspar rather than the pink form.
Igneous rock (from the Latin igneus meaning of fire) is one of the three main rock
types, the others being sedimentary and metamorphic. Igneous rock is formed
through the cooling and solidification of magma or lava. Igneous rock may form
either below the surface as intrusive (plutonic) rocks or on the surface as extrusive
(volcanic) rocks. (Wikipedia)
Driving south from Moruya, you can see fine exposures of the granite in the road
cuttings along the highway.
Granite breaks down easily to produce the rich soil beloved by farmers, and a
landscape of gently rounded hills. Right through the region almost all of the dairy
farms producing the famous Bega Cheese are on granite based soils, identified by
the granite boulders dotted across the paddocks. These boulders are easily seen