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
Indonesian Throughflow Indonesian Throughflow The Indonesian throughflow (ITF) is an ocean current with importance for global climate since it provides a low-latitude pathway for warm, fresh water to move from the Pacific to the Indian Ocean and this serves as the upper branch of the global heat conveyor belt. Higher ocean surface topography in the western Pacific than in the Indian Ocean drives upper thermocline water from the North Pacific through the western route of the Makassar Strait to either directly exit through the Lombok Strait or flow eastward into the Banda Sea. Weaker flow of saltier and denser South Pacific water