Coal and gold can be mined open cast in New Zealand. Once mining has finished, the site is rehabilitated, see below.
Essentially, overburden is removed, the exposed ore is recovered, and the pit is filled, progressively, by the next tranche of overburden or stockpiled overburden, depending on final land use when mining is completed. Blasting may be used to fracture rock to make excavation easier.
The working footprint of an open cast mine, such as Macraes gold mine in Otago, would typically be up to 300ha although the total area mined over time would be much greater than that.