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
St Brides Major (community) St Brides Major, the Dunraven estate and Clemenstone Meadow SSSI. Much of the coastline of the community is designated as the Southerndown Coast SSSI, both for its geology and botanic value. The stretch of shore, cliff, cliff-top, and several short, steep valleys, reveal the local geological strata. Carboniferous Limestone from upwards of 300 million years ago lies at the present sea level. By the Triassic period, 200 million years ago, these rocks were already tilted and eroded. A new deposition phase created more sedimentary rocks, including a red Triassic conglomerate, and a creamy white Jurassic limestone known as Sutton Stone,