46 Plate Motion Through Geologic Time
Elizabeth Johnson
How has the Surface oF Earth Changed through Time?
Watch these two videos which show the history of plate tectonics from 750 million years ago to today, and a shorter 240 million year history followed by an extrapolation of plate tectonics 250 million years into the future:
How do we know this?
These animations are plate reconstructions based upon ideas and data from geologic maps. Each geologic map is a visual representation of a hypothesis, or testable explanation, of the geologic events that location has experienced.
One of the goals of this module is to interpret the geologic maps in terms of plate tectonic forces: compression, tension, or shear (see Motion at Plate Boundaries and Geologic Structures and Plate Tectonics).
These interpretations are used to determine the type of plate boundar(ies) which existed in the past.