 As the North American Plate drifted west and the Insular Plate drifted east to the continental margin of Western Canada, the Bridge River Ocean began to close by ongoing subduction under the Bridge River Ocean.This subduction zone eventually jammed and shut down completely 115 million years ago, ending the Omineca Arc volcanism and the Insular Islands collided, forming the Insular Belt.Compression resulting from this collision crushed, fractured and folded rocks along the continental margin.