What was the tectonic evolution of western North America beginning with the Permian and through the Mesozoic?

Question

Quizplus · Accepted Answer

The Answer is During the Permian,an island arc and ocean basin formed off western North America,and then an oceanic plate subducted beneath the island arc.Oceanic and island arc rocks were thrust eastward against the craton during the Permian-Triassic boundary.In the Early Mesozoic,western North America became an oceanic-continental convergent plate boundary,with a steeply dipping subduction zone as North America moved over the Pacific plate.

What Was the Tectonic Evolution of Western North America Beginning