Investec has become the latest asset manager to peg back its earnings estimates for diversified miners due to the continuing slump in iron ore prices, with its analysts going so far as to declare "the commodity super-cycle officially over". It's debatable whether the buoyant price environment of recent years was ever cyclical in nature - but that's another story. Still, with prices down 43 per cent through 2014, it's understandable why the general analyst view has become resolutely downcast.