This EarthCache is located north of Grande Cache approximately 18 km on Highway 40 and just south of the current Grande Cache Coal mine lease. It is on public land and alongside the highway. There are places along the highway to pull off but please be careful crossing the highway and pulling on and off the highway to access this cache. It is the very noticeable coal seam embedded in the sedimentary rock formation alongside the highway. This area is visited by college and university groups to look at and study this geological formation. There is also a very cool walled off test mineshaft in the middle of this coal seam. You do not have to climb on anything to get a coal sample as there are many pieces of coal that have fallen down to the bottom of this formation.
Coal is a fossil fuel that is created by organic material (plant remains) being trapped in between layers of sedimentary rock. Over time the weight and pressure of the earth causes a chemical change in this material creating a carbon dense and rich substance called coal. There are different types of coal based on its carbon and moisture content. Coal is classed into four types: lignite, subbituminous, bituminous, and anthracite. (ordered from less quality to highest quality) In more basic terms, coal is either “Thermal Coal” or “Metallurgical Coal”. The coal in the Grande Cache area is classified as Metallurgical Coal and is mined and sold to steel mills around the world as its high carbon content is used in the steel production process. Thermal Coal has a lower carbon content and is the basic coal used in power plants to produce energy.
To log this EarchCache, visitors will need to pick up a sample of coal from this area and do the following basic coal sample tests.
1. Colour- the colour of coal ranges from grey to black.
- Grey- coal that is the colour grey is of poor quality with high moisture and ash content and a low carbon and calorific (heat) value.
- Light black- coal that is light black is of medium quality.
- Deep Black- coal this is deep black is of high quality with low moisture and ash content and high carbon and calorific value.
Identify the colour of coal in this area.
2. Lustre- the luster of coal is defined as how shinny it is and ranges from dull to shinny and is an indicator of its calorific (heat) value.
- Dull Lustre- coal is of poor quality with a low calorific value
- Shiny Lustre- coal is of high quality with a high calorific value
Judge the overall lustre of coal in this area.
3. Hardness- the hardness of coal ranges from soft to hard.
- Soft Coal- if the coal breaks by pressing it between both your hands then it is classified as a soft coal. Soft coal that is black in colour is of high quality. Soft coal that is brown in colour is of low quality, as it has not yet fully formed.
- Hard Coal- if the coal can NOT be broken by your hands then it is a hard coal. Hard coal is generally of poor quality.
Judge the overall hardness of coal in this area.
Final analysis question: Based on these observations, do you think the coal seam at this location is high quality or low quality coal?
Please submit your answers to the above 4 questions/coal sample tests in an email to my cache owner’s profile. Please do not submit them in your log. Thank you and enjoy this EarthCache!
