Circum-Superior Belt sills. Geochemical indications suggest that the overlying Flaherty volcanics might also have relationships with the Povungnituk volcano-sedimentary group in the Cape Smith Belt, indicating the Flaherty volcanics might be 2,040 to 1,960 million years old. Sills on the Belcher and Snowy islands in Hudson Bay are dated to 1,870 million years old, indicating the 1,880 million-year-old magmatism also exists in this section of the Circum–Superior large igneous province. The Fox River Belt in northern Manitoba is composed of sediments, volcanics and sills. Fox River Belt sills and Molsen dikes are 1,883 million years old, but the Molsen dikes at the
Circum-Superior Belt extend over across the western portion of the Superior craton from near the Fox River Belt in the north to near Lake Superior in the south. This magmatic crossing creates a relationship with the 1,880 million-year-old magmatism in the northwestern portion of the Circum-Superior Belt and magmatism in the Marguette Range Supergroup on the southern portion of the Circum-Superior Belt. In addition, the north-northwest trend of the Pickle Crow dikes and the absolute north-northeastern trend of the Molson dike swarm combine to an area north of the northwestern portion of the Circum-Superior Belt. This might determine the zone of a