The Coal Mines Historic Site is an outstanding example of the 19th-century European global strategy of using the forced labour of convicts. Illustrating the importance of labour and production, classification, punishment and surveillance in the penal system and the role of the convict in the establishment of colonial economies.
Coal (from the Old English term col, which has meant “mineral of fossilized carbon” since the thirteenth century) is a combustible black or brownish-black sedimentary rock usually occurring in rock strata in layers or veins called coal beds or coal seams. The harder forms, such as anthracite coal, can be regarded as metamorphic rock because of later exposure to elevated temperature and pressure. Coal is composed primarily of carbon along with variable quantities of other elements, chiefly hydrogen, sulphur, oxygen, and nitrogen.
Throughout history, coal has been used as an energy resource, primarily burned for the production of electricity and/or heat, and is also used for industrial purposes, such as refining metals.
Coal is formed in sedimentary basins. Sedimentary basins are regions where the Earth has subsided or sunk down. Water and sediments then flow into the basin and they fill with layers of sediments. Australia's black coal resources range from Permian to Jurassic in age (299 to 145 million years old), although most are Permian in age. During this time, the climate was warm in Australia, and Eastern Australia was covered by large, meandering rivers, marshes, bogs and swamps. The sediments deposited in these environments eventually formed rocks such as shale, sandstone and coal. Brown coal in Australia formed more recently than the black coals. These are mostly of Paleogene age (66 to 23 million years old).
Coal is a sedimentary rock formed when abundant plant material is covered by sediments and the material accumulates faster than it can decay. The weight of the overlying sediments compacts the organic layers, increasing the temperature and pressure, which leads to physical and chemical changes to the plant material. Water, carbon dioxide and methane are produced and escape, so the material becomes progressively enriched in carbon. With increasing time, and higher heat and pressure, the plant material first forms into peat, then is converted into brown coal, then sub-bituminous coal, bituminous coal, and lastly anthracite.
The posted coordinates are a starting point for your walk to complete this EC, there is some interesting historical and geological information currently available here, although there is no direct question relating to this exact information, we encourage you to read it as it will enhance your experience of the site. Reference point 1 is where you will find the main building, there are no direct questions relating to this area either. To log your find, please answer the following questions:
Q1, WP1 will have you standing at the main shaft for the coal mine, How deep down the shaft can you see coal, is there much there, why do you think it is still there?
Q2, As you wander down to WP2 you are literally walking in the footsteps of the convicts, this was the exact path they took down to Plunkett Point, take note of the geology beneath your feet, arriving at WP3, you will need to look at the ground, can you see the small Ant hills? These are called ant-beds (the things you learn while caching), ant-beds give us a good picture into the strata beneath our feet, can you describe what the ant-beds are made up of? Using the information, you have learnt from this page and this site can you name what this might be?
Q3, A photo of you or a personal caching item at the Coal mines Historic Site.
You are welcome to log your find straight away to keep your TB's and Stats in order but please message us with your answers within a couple of days. Cachers who do not fulfil this Earth Cache requirement will have their logs deleted without notice.
Source: lumenlearning, Geoscience Australia.