Perhaps Great Noligwa is a good example of mine depth. It goes 2.4km below surface and its maximum mining depth is 2.6km below surface. The deepest mines are all in South Africa and currently the deepest mine reaches four kilometres! Deep mining at 1000 m is apparently normal.
Coal mine depth has reached 1500 m, and as for geothermal work, this has reached more than 5000 m. The deepest mines are for oil and gas/ These have reached around 7500 metres. The problem with averages is that they obviously change each time a mine exceeds the existing record for depth.
