Regarded as one of Australia's Big Things, the granite sculpture stands at 8 metres (26 ft) in height, and weighs in the vicinity of 70 tonnes. It took 17 years to produce from initial proposal to the final unveiling in 2009, and two years to carve. The stylised work of a farmer represents the early settlers of the region, with carvings symbolising grain and sheep found within the sculpture.
Granite is a common type of felsic intrusive igneous rock that is granular and phaneritic in texture. Granites can be predominantly white, pink, or gray in color, depending on their mineralogy. The word "granite" comes from the Latin granum, a grain, in reference to the coarse-grained structure of such a holocrystalline rock. By definition, granite is an igneous rock with at least 20% quartz and up to 65% alkali feldspar by volume. It is the presence of potassium feldspar that gives many granites a distinctive pink colour.
Granite is nearly always massive (lacking any internal structures), hard and tough, and therefore it has gained widespread use throughout human history, and more recently as a construction stone.
Granite has been intruded into the crust of the Earth during all geologic periods, although much of it is of Precambrian age. Granitic rock is widely distributed throughout the continental crust and is the most abundant basement rock that underlies the relatively thin sedimentary veneer of the continents.
Granite is a natural source of radiation, like most natural stones. However, some granites have been reported to have higher radioactivity, thereby raising some concerns about their safety.
Potassium-40 is a radioactive isotope, and a constituent of alkali feldspar, which in turn is a component of granitic rocks.
Some granites contain around 10 to 20 parts per million (ppm) of uranium. Thorium also occurs in all granites as well. Radon gas generated by radioactive decay of uranium and thorium poses significant health concerns.
To log this earthcache please email me the answers to the following questions.
Q1, What colour granite is in this sculpture? What is it that gives this particular granite this distinctive colour?
Q2, How have the square blocks on ground level around the memorial been cut? What evidence can you see?
Q3, Granite is a natural source of "what"? Why is this issue a concern?
Q4, What is the difference in surface condition between the base and top of column in the centre of the sculpture ?