Volcanology of Canada - Western Canada

Western Canada

The Flin Flon greenstone belt in central Manitoba and east-central Saskatchewan is a collage of deformed volcanic arc rocks ranging in age from 1,904 to 1,864 million years old during the Paleoproterozoic sub-division of the Precambrian period. Volcanic activity between 1,890 and 1,864 million years ago produced calc-alkaline andesite-rhyolite magmas and rare shoshonite and trachyandesite magmas while the 1,904 million year old arc volcanism occurred in one or more separate volcanic arcs that were possibly characterized by rapid subduction of thin oceanic crust and large back-arc basins. In contrast, the younger 1,890 million year old volcanics indicate evidence of crustal thickening. This was due to long-term growth of the volcanic arcs by continuous volcanic activity and tectonic thickening associated with arc collisions and successive arc deformation. This in turn followed a massive mountain building event called the Trans-Hudson orogeny.

The Cretaceous era 145-65 million years ago was a period for active kimberlite volcanism in the Western Canadian Sedimentary Basin of Alberta and Saskatchewan. The Fort à la Corne kimberlite field in central Saskatchewan formed 104 to 95 million years ago during the Early Cretaceous. Unlike most kimberlite fields on Earth, the Fort à la Corne kimberlite field formed during more than one eruptive event. Its kimberlites are among the most complete examples on Earth, preserving kimberlite pipes and maar volcanoes. The Northern Alberta kimberlite province consists of three kimberlite fields known as the Birch Mountains, Buffalo Head Hills and the Mountain Lake cluster. The Birch Mountains kimberlite field consists of eight kimberlite pipes known as Phoenix, Dragon, Xena, Legend and Valkyrie, dating approximately 75 million years old. The Buffalo Head Hills kimberlite field was dominated by explosive kimberlite volcanism from 88 million years ago to 81 million years ago, forming maars. Kimberlites of the Buffalo Head Hills field are similar to those associated with the Fort à la Corne kimberlite field in central Saskatchewan. The kimberlite pipes of the Mountain Lake cluster were formed during a similar timespan with the Birch Mountains field 77 million years ago.