Polar forests of the Cretaceous Polar forests of the Cretaceous Cretaceous polar forests were temperate forests that grew at polar latitudes during the final period of the Mesozoic Era, known as the Cretaceous Period 145–66 Ma. During this period, global average temperature was about higher and carbon dioxide (CO) levels were approximately 1000 parts per million (ppm), 2.5 times the current concentration in Earth's atmosphere. The abundance of atmospheric carbon dioxide had a very significant impact on global climate and Earth's natural systems as its concentration is considered one of the main factors in the development of a pronounced greenhouse Earth during the Cretaceous with
Volcanology of Canada Jurassic and Cretaceous periods. The source for this volcanism was a long-lived and stationary area of molten rock called the New England or Great Meteor hotspot. The first event erupted kimberlite magma in the James Bay lowlands region of northern Ontario 180 million years ago, creating the Attawapiskat kimberlite field. Another kimberlite event spanned a period of 13 million years 165 to 152 million years ago, creating the Kirkland Lake kimberlite field in northeastern Ontario. Another period of kimberlite volcanism occurred in northeastern Ontario 154 to 134 million years ago, creating the Lake Timiskaming kimberlite field. As the North American