The Erith Coal Mine Track is a 2km loop bushwalk which takes approximately one hour with some steep sections. It takes you to the now abandoned Erith Coal Mine, which is located in the wall of a very picturesque waterfall canyon and is safely accessible via metal platforms and staircases. For safety reasons the mine entrances are closed but you can examine the exposed coal seam and enjoy the beautiful surroundings on the walk and at the mine entrance. Note that there is a park access fee of $8 at the time of writing and the park gates may be closed outside of daylight hours.
To get to GZ: I have provided several waypoints. My recommendation is to park at the parking waypoint, then walk to the "Start of Erith Coal Mine Track" waypoint. From there you can make your way along the formed trail to the waypoint "Above the Mine Entrance". Here you cross a small creek then descend via metal stairs and platforms to the mine entrance itself, which is at the published coordinates. Once you have finished enjoying the area and answering the questions below, you can return to the track via the same stairs and then either return along the track in the direction you came, or continue on to finish the loop and return along the road to the parking waypoint.
Some information about coal: Coal is a combustible black or brown sedimentary rock which usually occurs in layers called coal beds or coal seams. The harder forms can be considered metamorphic rock because of their later exposure to elevated temperature and pressure. Coal is composed primarily of carbon, along with varying quantities of other elements, typically hydrogen, sulfur, oxygen and nitrogen. Coal is formed when dead plant matter is converted into peat which is later buried under other sediment. Over millions of years the weight of the sediment above causes higher temperatures and pressures, which changes the chemical composition of the peat. Typically the material progresses through lignite (soft moist brown coal), to bituminous coal (harder tar-bearing coal) and finally anthracite (hard black coal).
To claim a find on this Earthcache, you must visit the published coordinates, make some observations and send me your answers:
1. At the bottom of the stairs, at the entrance to the old mine, there is an impressive column formed from the exposed coal seam, sandwiched between sandstone above and the floor below. Approximately how thick from top to bottom is the coal seam here?
2. Examine the top band of coal in this column, directly under the sandstone layer above. Describe the appearance of this band of coal. Do you think this is lignite (soft moist brown coal) or anthracite (hard shiny black coal)?
3. Choose another band in the column of rock which has a different appearance. Describe its approximate position in the column, and the differences in appearance between this band and the top band.
Photos are always welcome, but please no spoilers. You may post your Found log immediately without waiting for my response. If I don't receive correct answers within 7 days of your Found log being posted, I may delete your log. Please don't post spoilers in your log.