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 III stand out". Ring of Fire III Ring of Fire III is an anthology created by editor-author-historian Eric Flint, first published in hardcover by Baen Books in July 2011. It is the third anthology in the 1632 series following after "Ring of Fire II" (2008). The book includes twenty short stories, together with a preface by the editor. The Preface by Eric Flint explains the contents of this anthology and mentions future works. The reviewer for SFRevu said that "this collection contains high quality and stories that are important to the development of the 1632 universe" and that "fans of the