And the gold rush of 1849, which caused an inflationary blip, too. But these things tend to settle out a hell of a lot faster when there's no printing press going full-speed.
It's also self-correcting somewhat. Once the price of gold falls in such a scenario, the incentive to mine/conquer
more drops greatlyCorrection, - the incentive to mine more increases (motivation for innovation), but one's ability to mine more is diminished by the decrease in value (without innovation). Ones will to mine the same amount for a lower return is diminished, hence in the absence of innovation, mining more gold is diminished and the self-correcting equilibrium is restored.
You put the cart before the horse. The motivation for innovation is to reduce costs. It tends to create an increase in production which in turn suppresses prices (in a properly competitive system).