Mesozoic+Era

The Mesozoic Era
The Mesozoic era lasted about 180 million years and marked the beginning of the breakup of Pangaea. At various times during the Mesozoic period, seas and swamps covered much of central and western Canada. While this area was under water, new layers of sedimentary rock formed on top of those formed in the Paleozoic era.

 As Pangaea broke up, the North American plate moved westward and collided with the Pacific plate. This caused huge amounts of magma to rise to within a few kilometres of the surface of the North American plate. Here it cooled and solidified into a large mass of granite. This granite structure was later uplifted and formed the Coast Range Mountains. The tremendous tectonic forces also began to fold the earth's surface to form the Rocky Mountains toward the end of the Mesozoic era. The Innuitian Mountains were formed in the eastern Arctic as the North American plate moved in a northward direction.

1. During the Mesozoic era, the North American plate collided with the Pacific plate. What resulted from this collision?

 The climate of the land mass that is now Canada was still warm during much of the Mesozoic era. Dinosaurs and other reptiles roamed through huge swamps and forests. Many dinosaurs lived on the shores of the great inland sea to the east of the Rocky Mountains. Evidence of these huge animals has been found in the layers of sandstone along the Red Deer River in southern Alberta. Dinosaur Provincial Park now exists there to protect these 75 million-year-old fossils.

 Vegetation in swamps was covered with sand and silt. Layers of sediments compressed the layers of vegetation to form the coal deposits now found in southern British Columbia, Alberta, and Saskatchewan. In the shallow seas that periodically covered the Interior Plains, the remains of tiny sea creatures and plants fell to the sea floor and were covered by sediments. As the sediments piled up they were compressed into sedimentary rock. Pressure from the weight of the rock, bacteria, and heat changed the plant and animal remains into oil and gas.

2. How were (i) coal deposits and (ii) oil and gas deposits formed in western Canada during the Mesozoic era?

 The end of the Mesozoic era was marked by another mass extinction. More than half of all plant and animal species, including the dinosaurs, became extinct. No one is quite sure of the cause, although scientists have many theories, including the possibility that the earth collided with a giant asteroid.