Ring of Fire of the Andes, hence the name sometimes used by geologists: "Antarctandes". At the opposite side of the continent, the volcanoes of Victoria Land may be seen as the 'other end' of the Antarctandes, thus completing the Pacific Ring of Fire and continuing up through the Balleny Islands to New Zealand. Mount Erebus is the second-highest volcano in Antarctica (after Mount Sidley) and the southernmost active volcano on earth. It is the sixth-highest ultra mountain on an island. With a summit elevation of , it is located on Ross Island, which is also home to three inactive volcanoes, Mount Terror, Mount
Circum-Superior Belt margin. The last collision occurred on the southeastern portion of the Superior craton to produce the Grenville orogeny 1,100 million years ago. Because most of the Circum-Superior Belt was formed by widespread mafic-ultramafic magmatism 1,884 to 1,864 million years ago along the Superior craton margin during these orogenies, a number of different suggestions have been made to explain the questionable origins of this large igneous province. It is also not clear if the Circum-Superior Belt has a single origin or it has several origins. Suggestions include back-arc rifting, foredeep flexure, mantle plumes and the breakup of a microcontinent. The geochemical