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
Lake Parime the Takutu Basin or the Takutu Formation, dates back to the late Paleozoic, roughly 250 million years ago, and the basin connected with the Atlantic via the Takutu Graben. The geologic history of the Takutu Graben is characterized by one phase of volcanic activity and three depositional phases of sedimentary rocks. Rifting (due to divergent tectonic plate movements) occurred in "a lake or delta environment" in the Late Triassic to Early Jurassic periods, between 200 million and one hundred and fifty million years ago. Starting around 66,000 years ago, sea level rise and more humid conditions created flooded zones north