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 II Ring of Fire II Ring of Fire II is a 2008 anthology created by editor-author-historian Eric Flint. It is the second anthology in the 1632 series following after "Ring of Fire" (2004). The initial Ring of Fire book was a notable departure in that it heralded a new era in writing series fiction by being set in an authors' milieu shared with other writers, but especially and uncharacteristically by doing so without the control of the milieu creator, its author. Flint, in explanation, has self-styled himself as something of a gambler; he demonstrated that by deliberately asking the other writers