When I first posted my entry for hydrothermal veins a few years ago, I noted that they can have a history related to earthquakes: each time a fracture opens a little bit farther during a quake, mineral-bearing fluids come in to fill the gap and quickly crystallize. Now a paper in Nature Goscience by a pair of Australian geoscientists proposes a highly dramatic scenario, but a reasonable one, in which these deep cracks open so swiftlyat the speed of sound in rocksthat the fluids actually flash into vapor. Any gold in solution would find itself, in effect, suspended in midair and quickly form films and nanoparticles of gold metal. These would grow as quakes repeat. And that's how most gold deposits form, they say. Even little earthquakes can do this work, they calculate.
It seems to me that the same simple piston model the authors used could be replicated in the lab, using something as simple as sledgehammer blows to vaporize microfractures. Enterprising students, take note.