This is another in our ''Remembering the Fallen'' series, it is the 2nd Earthcache in the series, which will take you to the Australian War memorial in Canberra. Please complete the earth cache and then take the time to have a walk around and through the Memorial. Whenever we go we end up taking at least a couple of hours which is worthwhile to remember those who gave their lifes for our benefit.
A lot of cachers avoid earthcaches due to their perception that they are difficult but we have made this earth science lesson easy to help get more people interested.
The Australian War Memorial
The Australian War Memorial is Australia's national memorial to the members of its armed forces and supporting organisations who have died or participated in wars involving the Commonwealth of Australia. The memorial includes an extensive national military museum. The Australian War Memorial was opened in 1941, and is widely regarded as one of the most significant memorials of its type in the world.
The Australian War Memorial consists of three parts: the Commemorative Area (shrine) including the Hall of Memory with the Tomb of the Unknown Australian Soldier, the Memorial's galleries (museum) and Research Centre (records). There is also has an outdoor Sculpture Garden. The Memorial is currently open daily from 10am until 5pm, except on Christmas Day. Entry is free, but you are not required to enter the Memorial to gather the information required, and the required area is available 24/7
The building has been constructed of brick walls, and faced externally with Hawkesbury Sandstone.
Sandstone
Sandstone is a clastic sedimentary rock composed mainly of sand-sized (0.0625 to 2 mm) mineral particles or rock fragments.
Most sandstone is composed of quartz and/or feldspar because they are the most resistant minerals to weathering processes at the Earth's surface. Like uncemented sand, sandstone may be any color due to impurities within the minerals, but the most common colors are tan, brown, yellow, red, grey, pink, white, and black. Since sandstone beds often form highly visible cliffs and other topographic features, certain colors of sandstone have been strongly identified with certain regions. Rock formations that are primarily composed of sandstone usually allow the percolation of water and other fluids and are porous enough to store large quantities, making them valuable aquifers and petroleum reservoirs. Fine-grained aquifers, such as sandstones, are better able to filter out pollutants from the surface than are rocks with cracks and crevices, such as limestone or other rocks fractured by seismic activity.
Hawkesbury Sandstone
Six kilometres of sandstone and shale lie under Sydney. In Sydney sandstone, the ripple marks from the ancient river that brought the grains of sand are distinctive and easily seen, telling geologists that the sand comes from rocks formed between 500 and 700 million years ago far to the south. This means that the highest part of the visible lines almost always faces approximately south. It is a very porous stone and acts as a giant filter. It is composed of very pure silica grains and a small amount of the iron mineral siderite in varying proportions, bound with a clay matrix. It oxidises to the warm yellow-brown colour that is notable in the buildings which are constructed of it.
The sand was washed from Broken Hill, and laid down in a bed that is about 200 metres thick. Currents washed through it, leaching out most of the minerals and leaving a very poor rock that made an insipid soil. They washed out channels in some places, while in others, the currents formed sand banks that show a characteristic current bedding or cross-bedding that can often be seen in cuttings.
At a time in the past, monocline formed to the west of Sydney. The monocline is a sloping bend that raises the sandstone well above where it is expected to be seen, and this is why the whole of the visible top of the Blue Mountains is made of sandstone. From the beginnings of the colony in 1788, settlers and convicts had to work with the stone, using it for building and trying to grow crops on the soil over it. The sandstone had a negative effect on farming because it underlay most of the available flat land at a very shallow depth.
In the late 19th century, it was thought that the sandstone might contain gold. Some efforts were made at the University to test this idea. Reporting on them in 1892, Professor Liversidge said "The Hawkesbury sandstone and Waianamatta shale was, of course, derived from older and probably gold-bearing rocks hence it was not unreasonable to expect to find gold in them."
The sandstone is the basis of the nutrient-poor soils found in Sydney that developed over millennia and 'came to nurture a brilliant and immensely diverse array of plants'. Sandstone escarpments box in the Sydney area on three sides: to the west the Blue Mountains, and to the north and south, the Hornsby and Woronora plateaux'. These escarpments, avoided by the early settlers, kept Sydney in its bounds and some people still regard the spatial boundaries of the city in these terms. Other rock types found in Sydney include Narrabeen shale and the younger Wianamatta shale and Mittagong formation
Logging requirement:
To Log this EarthCache, please send an email with answers to the following questions to our Geocaching.com account.
At GZ you will be facing the external wall of the war memorial.
1. Your caching name and the EarthCache name
2. Looking at the wall in front of you what are the 3 prominent colour's of stone making up the Sandstone?
3. Touch the wall, what texture is it ?
4. Explain in you own words, why it has this texture?
5. If you like include a photo of yourself at GZ, but please don’t include a picture of any of the questions as we will need to delete the photo.
Ref:
https://en.wikipedia.org/wiki/Australian_War_Memorial
The history of the Australian War Memorial building / [Beryl Strusz].
https://en.wikipedia.org/wiki/Sandstone