Volcanic Bombs

Once upon a time pre-Covid we learned of a incredibly unique petrified wood deposit in northern Nevada near the town of Jackpot. It was discovered by a fellow from Wisconsin named Clete King. We tried to contact Clete to learn more about the occurrence but he wouldn’t answer his phone. Nor would he write us back after sending him numerous letters. Out of frustration we found his daughter and called her. Turns out Clete wasn’t trying to be rude – he just happened to be dead. We were a year too late. Too bad, we would have really enjoyed meeting him. Anyway we eventually found out exactly where Clete had dug his hole and went out to look for ourselves. It’s way out in the deserts of Elko County. Alas, there’s not much left – old Clete got nearly all of it (it was a small deposit). All we found was an old weather research balloon that had crash-landed nearby, which we dutifully packaged up and sent back to the researchers as requested. By now you’re probably thinking: “So what the hell does all this baloney have to do with Volcanic Bombs?” Good question: Turns out the trip was not entirely without reward. In a region to the northeast of Clete’s site our friends discovered some incredible volcanic bombs weathering out of Pliocene strata and laying atop the surface. A great bonus is that the insides of the bombs are often filled with chalcedony that fluoresces a nice vibrant green.

How They Formed

These unusual rocks formed when a volcano ejected thick, viscous globs of lava high into the air, during a violent eruption. As the molten magma flies through the air, it is often spinning and acquires an aerodynamic shape as a result. Volcanic bombs can be very large and may travel many miles from the vent where they originated. During it’s flight, it cools and hardens before falling back to Earth. If it lands in relatively soft sediments – in this case volcanic ash – then the bomb is preserved. After being deeply buried, quartz-rich solutions coated the inside of these bombs with chalcedony. Afterwards, the area was uplifted by the nearby mountains and the overburden eroded away, exposing the bombs and the petrified wood that Clete found. It would have been fun to trade Clete some volcanic bombs for petrified wood. But I guess that will have to wait until later- hopefully much, much later! – when we catch up with him.