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
USS Merapi (AF-38) Galveston Dry Dock Co., "Merapi" hastened through shakedown and departed Mobile, Alabama, 11 April, for the Pacific Ocean war zone. Specializing in refrigerated stores, she sailed via Pearl Harbor to Kerama Retto, Okinawa where in the midst of numerous air alerts she unloaded 14 to 19 June. Having retired to Pearl Harbor for more supplies she got underway again on 20 July and spent the final month of the war at Eniwetok Atoll disbursing cargo. In the postwar period "Merapi" provided logistic support for U.S. occupation forces, initially using Auckland, New Zealand, as her supply base. Spending much of 1946