Uranium ore support a neutron-mediated chain reaction). Uranium, thorium, and potassium are the main elements contributing to natural terrestrial radioactivity. Uranium has the highest atomic weight of the naturally occurring elements and is approximately 70% denser than lead, but not as dense as tungsten, gold, platinum, iridium, or osmium. It is always found combined with other elements. Along with all elements having atomic weights higher than that of iron, it is only naturally formed in supernova explosions. The primary uranium ore mineral is uraninite (UO) (previously known as pitchblende). A range of other uranium minerals can be found in various deposits. These
Galena, Oregon office moved from the current site of Galena two miles up Elk Creek to their mine. The new post office was named for a body of galena ore in the area, and the town was renamed as well. The mines were worked extensively in the 1860s and were still active in 1940. Galena, Oregon Galena is an unincorporated community in Grant County, Oregon, United States, about from Austin Junction in the Blue Mountains. It is on the Middle Fork John Day River in the Malheur national forest. The former gold mining camp is considered a ghost town. The locale was