Base metals prices are likely to remain high for the foreseeable future, says Merrill Lynch Commodities managing director Craig Tuckman, and this will have a significant impact on metals that take time to move from exploration to mining stage. How deep the price pullback will eventually be remains to be seen, but a reversion to the mean is not likely, he adds. "Over time, supply and demand will rebalance," he notes, speaking at the World Mining Investment Congress in London.