Explore a historically preserved gold mine in California’s Sierra Nevada mountains and learn how earthquakes bring gold to the surface, in this video from NOVA: Making North America: Human. Geologist Lisa White points out that quartz veins can contain gold and explains why this happens. As earthquakes fracture rocks, the cracks provide pathways for superheated water from deep in the Earth to rise. As the water rises, it cools and the minerals it carries crystallize. Over time, this forms a vein of quartz.