How are Northern plateau forms
Answers
Flat areas of rock are uplifted to form a plateau. For plateaus formed by extrusion, the rock is built up from lava spreading outward from cracks and weak areas in the crust.
Formation From Under the Earth's Surface
Many plateaus form as magma deep inside the Earth pushes toward the surface but fails to break through the crust. Instead, the magma lifts up the large, flat, impenetrable rock above it. Geologists believe a cushion of magma may have given the Colorado Plateau its final lift beginning about ten million years ago.
Repeated lava flows that spill out from cracks in the ground and spread out over hundreds of square miles can also slowly build up massive plateaus. The Columbia Plateau in the U.S. Pacific Northwest and the Deccan Plateau of west-central India were formed by these runny lava flows.
Plateaus also form in the ocean, such as the Mascarene Plateau in the Indian Ocean, one of the few underwater features clearly visible from space. It extends approximately 770 square miles (2,000 square kilometers) between the Seychelles and Mauritius Islands.