What was the name for the tectonic force that moved the North American Plate westward, breaking it away from Europe and Africa, colliding it with the Pacific Plate

Mantle convective current

Explanation:

The North American Plate is a tectonic plate that covers most of North America, Greenland, Cuba, the Bahamas, extreme northeastern Asia, and parts of Iceland and the Azores. It is Earth's second largest tectonic plate, behind the Pacific Plate. It is thought to be moved by the very slow creeping motion of Earth's solid silicate mantle caused by convection currents carrying heat from the interior to the planet's surface.