Circum-Superior Belt event in Australia and 1,860 million year old magmatism of the Mashonaland event in Africa. The other questionable suggestion related to the Circum-Superior Belt is the existence of a suggested 1,900 million year old global superplume event. The long Labrador Trough, extending from Ungava Bay through Quebec and Labrador, includes two volcano-sedimentary series, the first ranging from 2,170 to 2,140 million years old and second ranging from 1,883 to 1,870 million years old. This magmatism is considered to have formed as a result of back-arc volcanism. The youngest magmatic series (1883-1870 Ma) contains 1,880 million-year-old carbonatites and lamprophyres. 1,883 to
Circum-Superior Belt features are present in the Circum-Superior Belt, including dikes, sills and volcanics that comprise geologic formations. This geologic belt is considered to be a large igneous province because its magmatic rocks were emplaced over an extremely short geological time span. Even though the Circum-Superior Belt was emplaced during an extremely short geological time span, the associated magmas were probably derived from a number of separate sources. Most of the Circum-Superior Belt lies along the margin of the Superior Craton, which is the most extensive fragment of Archean crust on Earth. However, a number of igneous rocks within the Superior craton