Circum-Superior Belt northwestern Superior craton margin intrude an older, 2,090 to 2,070 million-year-old dike swarm. The Ospwagan Group is younger than and the 1,864 million-year-old Winnipegosis komatiite belt lies to the southwest. Numerous tectonic settings have been suggested for triggering magmatism in the Fox River Belt, including a marginal basin rifting event. At the southern portion of the Circum-Superior Belt, a group of fragmental sediments composed of iron formation was formed during a period of magmatic activity in the Marquette Range Supergroup. Included in the Marquette Range Supergroup is the Hemlock Formation, a bimodal volcanic group that is estimated to have an
Ring of Fire (Northern Ontario) Bay. The Ring of Fire was named when the first significant mineral finds were made in the region, by Richard Nemis, after Johnny Cash's famous country and western ballad. Nemis, the founder and president of Noront Resources, was a lifelong fan of the singer. Prior to its discovery, Canada and the United States were compelled to rely on offshore sources for chromite, principally from South Africa. By the fall of 2011, the Ring of Fire was considered "one of the largest potential mineral reserves in Ontario" with "more than 35 junior and intermediate mining and exploration companies covering an area