Ancient brines helped build Idaho's Silver Valley and Cobalt belt

Idaho's Silver Valley has produced about 1.2 billion ounces of silver since the late 1800s, enough to cast a solid cube roughly as tall as a five-story building, along with huge amounts of lead and zinc. Now a new study led by Washington State University researchers helps explain how mineral deposits in the Silver Valley and other mineralized parts of the Belt Supergroup began to form more than 1.2 billion years ago. The Belt Supergroup is a massive stack of rocks stretching across eastern Washington, Idaho, and Montana that also hosts the Idaho Cobalt Belt, the most significantly mineralized cobalt district in the United States.