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
Fire ring fireplace may be better used instead. These are designed to contain the entire fire instead of just keeping it in one place. A fire ring may be nothing more than a short, wide section of metal tube, partially buried in the ground. Slightly more advanced fire rings may be partially covered with metal bars so that the fire may be used for cooking. These types are seen at many campgrounds. Fire rings in urban areas, such as on beaches, may be made of poured concrete. Makeshift fire rings can be constructed out of a ring of stones where pre-constructed rings