Earth Sciences 2240F/G Lecture 19: Chapter 19

• School: Western University
• Department: Earth Sciences
• Course: Earth Sciences 2240F/G
• Professor: Sean Shieh

Document Summary

1. 0 the cretaceous period of the mesozoic era. The mesozoic era was dominated by the tectonic effects of the breakup of pangaea. Unusually rapid sea-floor spreading due to the opening of the atlantic in the cretaceous produced high mid-ocean ridges. Throughout the cretaceous, sea levels were high and there was an abundance of shallow warm seas again. In the first half of the cretaceous, global temperature was at least 8 c above that of today, making it the greatest greenhouse period with the highest atmospheric co2 since the precambrian. Marine and terrestrial life experienced a number of setbacks through the cretaceous, but it was nevertheless the most prolific period the earth had ever experienced. The interior of north america, for example, was virtually covered with herds of roaming dinosaurs of all different types. In the very late part of cretaceous, global temperature began to fall, but climate still was very warm relative to today.