Post by Dicky the Rockhunter on Dec 11, 2008 14:28:44 GMT -5
I knew that some mines and holes in the earth were big but ---these are amazing. sorry I cant paste them direct but it is worth the click.
Dicky has been wowed !!!
" The largest hand-dug excavation in the world.
The "Big Hole" was mined to a depth of about 800m [2625 feet] (depth of shaft = 1100m [3610 feet]). The distance from the surface to the layer of debris lying on top of the kimberlite pipe is about 215m [705 feet], including (in 2001) some 40m [131 feet] of water. It has a surface area of ±17 hectares [42 acres] and a perimeter of ±1.6km [1 mile]. It is the largest hand-dug excavation in the world. By 14 August 1914 22,7 billion kg [22.5 million tons] of rock had been excavated, yielding 2722 kg [2.7 tons] of diamonds. Underground mining was also eventually carried out at the Kimberley Mine, not just open pit mining.
ecotravel.ctaudubon.org/Photos/May082008.htm
