This is a 2-part Earthcache. It will require you to visit two (2) locations within the Illawarra. The first location is at the memorial to Australia’s worst coal mining disaster, located at Mount Kembla (posted coords). The second location is at the northern end of Austinmer Beach. S34° 18.321 E150° 56.223. It is here that you'll see a great example of naturally exposed coal.
Composition:
The composition of Coal is primarily Carbon with some secondary traces of Sulphur, Hydrogen, Oxygen and Nitrogen. Coal is classified by rank, which is a measure of the amount of alteration it has undergone during formation.
History:
Coal is a fossil fuel created from the remains of plants that lived and died about million years ago. In different parts of the world this has occurred at various times throughout the last 400 million years resulting in coal deposits of widely varying age an type across the globe. As dead plant matter fell into swampy waterways it would lay decaying at the bottom of swamps. Over time, the surface and climate of the earth changed, and more water and dirt washed into these areas, halting the decay process. The weight of the top layers of water and dirt packed down the lower layers of plant matter. Under heat and pressure, this plant matter underwent chemical and physical changes turning the decaying matter into peat. As further oxygen was pushed out rich hydrocarbon deposits remained. What once had been plants gradually turned into brown and black coal.
Uses:
Coal is used in a wide range of applications, primarily it is used as a source of fuel to produce electricity and heat via combustion. Generally the coal is pulverized and then burned in a furnace that in turn boils water to steam. Coking is another use of coal, the coal is baked at extreme temperatures without oxygen. This process burns off volatiles within the coal, leaving a product known as coke. The coke is used in blast furnaces in the production of steel. Coal gasification can be used to produce syngas, which is a mixture carbon monoxide and hydrogen gas. Syngas can then be converted into transportation fuels like gasoline and diesel. Coal also plays an important part in the production of cement powering the kilns which transform the raw products into clinker.
Coal In Australia:
Coal is classified as a non-renewable energy source and in Australia comes in two forms depending on the region. High quality black coal (low ash content) is found in QLD and NSW while lower quality brown coal (high ash and water content) is found in VIC and SA. 75% of all coal mined in Australia is exported, mostly to eastern Asia. Australia is the world leading exporter of coal.
Mining of Coal:
In Australia coal is extracted from the ground using 2 methods. Open-Cut (surface) mining is where coal is found close to the earth’s surface, by scraping the top layers away coal can be extracted easily. Heavy machinery such as draglines, large dump trucks and power shovels are used for extraction. The other method is underground (deep) mining, this requires a tunnel (portal/drift or shaft) to be drilled down to the coal seam. Once at the coal seam, "longwall" or "room and pillar" mining is used to extract the coal where it is then placed on large coveyors and brought to the earths surface.
Dangers of Coal Mining:
The mining of coal underground is a high-risk operation. Its dark, often wet, has heavy machinery constantly moving, dangers of roof collapse and there is a potential of gases being present. These pockets of trapped gases lie within the layers of coal and as the pockets of gas are released due to mining the potential for explosion is very high. In the early years of mining with limited 
gas detection, explosions were common. Unfortunately here in the Illawarra with the underground mining of the escarpment we haven’t been spared from these tragedies. In 1887 there was an explosion at the Bulli mine that resulted in 81 miners dying. Worse was to come, in 1902 there was an explosion at the Mount Kembla mine where 96 men and boys lost their lives, either while at work or trying to rescue others. The Mount Kembla mining disaster remains Australia’s worst mining disaster.
Claiming a find:
In order to log this Earthcache, you'll need to visit both waypoint locations and answer the following questions. Email your answers via the G.C profile for permission to log this cache. Logs without permission may be deleted. It is also preferable that you upload a picture of you/your group and your GPSr at one of the waypoint locations.
At Waypoint 1
S34° 25.946 E150° 49.150
- There is a large red wagon on display. What number is on the side and between what years did the waggon do continuous use?
- What are the 2 hand tools at the front of the arch.
- The black arch structure has what significance to the Mt Kembla mine?
- Near the church there is one of the last pieces of coal mined from the colliery. When was it placed at its current location?
At Waypoint 2
S34° 18.321 E150° 56.223
- Here you will easily see the coal seam come out of the ground and head towards the headland. How many distinct levels/layers of coal make up the coal seam.
- Describe the texture, colour, moisture & structure of the coal. You will get dirty doing this.
We hope you enjoy this insight into coal and its history within the Illawarra.
Reference
http://en.wikipedia.org/wiki/Coal_in_Australia
http://www.geotech.org/survey/geotech/coal.pdf
http://www.illawarracoal.com