My inaugural posting.
An article just recently published online in Nature Geoscience provides new insights into the origin of vein-hosted gold sytems (orogenic or ‘mesothermal‘ gold in the geological literature). Weatherly and Henley have proposed ideas that link fault systems, fluid flow, earthquakes, and the genesis of large, orogenic gold deposits, in terms of a thermomechanical piston model. Their results illustrate that fault jogs that are typically found associated with orogenic deposits become fluid-filled cavities during earthquakes. These depressurization of fluids as they enter these jogs results in flash vaporization and the fluid drops out gold and associated quartz. The results also illustrate that many large gold deposits form relatively rapidly on a geological time scale. The work also builds on previous work on “seismic pumping” (http://tinyurl.com/cdpmeop) and other studies that have shown how rapid gold deposits form from hydrothermal fluids (e.g., http://tinyurl.com/awhms9h)
The original article is here at Nature Geoscience: http://tinyurl.com/buemgvb (requires subscription).
A companion article from Scientific American can be found here: http://tinyurl.com/cls69l6.
I heard about this research on a radio podcast recently. It’s good to hear about these things from different sources.