Circum-Superior Belt age of . Another volcanic series in the Marquette Range Supergroup, known as the Gunflint Formation, has an age of . Further geologic units that are related to the Gunflint Formation include the Badwater volcanics and the Kiernan sills. A number of origins have suggested for the Marquette Range Supergroup magmatism. This includes subsidence being driven ahead related to thrusting of the Penokean orogeny or a possible back-arc basin, and lateral flow through the Pickle Crow dikes transported magma from the Fox River Belt area through the Superior craton for placement in the Marquette Range Supergroup. This suggested long-range origin
Circum-Superior Belt indication of the Circum-Superior Belt is also poorly known; either it contains major regional differences or it is the same throughout the magmatic zone. With the discovery of the Pickle Crow dike swarm throughout the western Superior craton, the likelihood of other 1,880 million year old dike groups throughout the Superior craton remains. This is partly because several dike zones in the Superior craton remain undated. The relationship of the Circum-Superior Belt with similar age magmatism throughout the nearby Trans-Hudson belt and elsewhere on Earth is also unknown. This includes the 1,860 million year old magmatism of the East Kimberly