Igneous Rocks. 
287 
granite is met at Moruya. The polished columns in 
the General Post Office colonnade are good examples of 
Moruya granite. The felspars are milk-white, and 
contrast well with the dark mica and almost black 
hornblende. The rock is remarkable for the abund- 
ance of black patch es, known as aggregates or inclu- 
sions. These patches are, in some instances, merely 
aggregates of the more basic portions of the rock. In 
other cases they represent portions of other rocks 
caught up while the rock was yet in a plastic condi- 
tion. At Gabo Island we have another granite, but of 
quite a different character. Here the felspars are a 
rich flesh colour, giving a warm tone to the rock. 
Granites present to the geological student many 
points of interest. They are all old, very old rocks. 
They form great basins, in which the sedimentary 
rocks lie cradled. Granite is in fact the solid founda- 
tion on which the upper world rests. When a series 
of Aqueous rocks are traced downwards, sooner or 
later granite is reached. If we only sink deep enough 
anywhere, we must ultimately come to granite or into 
allied rocks. But what is below granite no man knows. 
One feature characteristic of granite country is 
the great rounded masses of stone that crown the 
highest points. Boulder-like masses are seen piled 
one above the other, and often so delicately poised 
that apparently the least provocation would send 
them crashing from above. Someone has remarked 
that mountain-tops are usually in a fearful state 
of disrepair. Granite peaks are not an exception. 
