The widening intercontinental rift gradually forms a new ocean basin, the Atlantic Ocean. The rift region known as the Mid-Atlantic Ridge continues to provide volcanic material for the expanding ocean basin.
Meanwhile, North America is slowly being pushed eastwards. west from the rift zone. The thick continental crust that made up the new east coast collapsed into a series of fault blocks that ran roughly parallel to the current coastline. At first, the hot, faulted edge of the continent was high and buoyant relative to the new oceanic basin.
As North America’s belt moves away from the hot rift, it begins to cool and sag beneath the New Atlantic. This actively diverging plate boundary has become the passive westward moving edge of North America. In terms of plate tectonics, the Atlantic Plain is known as a classic example of a passive continental margin.
Today, the Mesozoic and Cenozoic sedimentary rocks are located beneath much of the Coastal Plain and the continental shelf is bordered almost horizontally.
What was Pangea and what happened?
The agglomeration of the continental blocks forming Pangea was well underway during the Devonian (419.2 million to 358.9 million years ago) during the Laurentian paleocontinent (a continental massif comprising the North American Paleocene. , i.e. the stable interior of the continent) and Baltica (a land mass made up of the ancient Eastern European bedrock) merged with several smaller subcontinents to form Eurasia.
Au early Permian (298.9 million to 252.2 million years ago), the northwest coast of the ancient continent of Gondwana (an ancient continent that would eventually split to become South America, India, Europe, and Africa). Africa, Australia and Antarctica) collided and merged with the southern part of Euramerica (an ancient continent comprising North America and Southern Europe).
With the amalgamation of the Angaran background in Siberia with this combined land in the mid-Permian, the Pangea assemblage is complete.
How did Pangea’s formation affect life on Earth?
Geologists suggest that the formation of Pangea seems to be partly responsible for the mass extinction event at the end of the Permian period, especially in the marine domain. As Pangea formed, the range of shallow-water habitats decreased and land-based barriers prevented the flow of cold polar water into the tropics.
This is thought to reduce levels of water. dissolved oxygen in the remaining warm water habitats and contributed to 95% of the reduction in marine species diversity. The disintegration of Pangea had the opposite effect: more shallow-water habitats emerged as the overall length of the coastline increased, and new habitats were created as channels between the lands were small. The intersection is opened and allows warm and cold ocean water to mix.
On land, plant and animal populations are fragmented, but life forms on new continents are isolated. have developed unique adaptations to their new environment over time, and biodiversity has increased.