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
Ring of Fire (anthology) Ring of Fire (anthology) Ring of Fire is the third published book by editor-author-historian Eric Flint of the 1632 series, an alternate history series begun in the novel "1632" (February 2000). The "Ring of Fire" is both descriptive of the cosmic event as experienced by the series' characters, but also is at times used as the name for the series itself. The series is set in war-torn Europe during the middle of the Thirty Years' War. "Ring of Fire" is a collection of short stories —half by a variety of established science fiction authors invited into the setting, half fan-fiction