A merry dance?
Plate tectonics is the all-embracing theory of how our planet works – how heat flow from the earth’s interior reaches the surface via convection currents in the mantle, which then drag on the lower surface of the crust. This interaction between mantle and crust creates sideways movement in the crust which breaks into massive blocks called plates. (Tectonics is a term derived from a Greek a word that implies movement). As the plates move, so molten material rises from the mantle to fill any gaps; massive earth quakes occur if there is sideways motion between plates, and violent volcanic eruptions happen where two plates collide. Plates collide, fuse together, then break up, sometimes along old boundaries, often along completely new boundaries.
Current plates and their movements are easy to spot; the Californian or Turkish earthquakes, the volcanic ring around the Pacific ocean, the symmetry between American east coasts and west coast of Europe and Africa for example.
But what about long ago…..before the plates we recognise? Ancient boundaries and events are recorded in our rocks if only we can recognise them.
A recent extremely detailed research paper “Earth’s tectonic and plate boundary evolution over 1.8 billion years” has resulted in a video that shows such plate movements. This more conversational and readable paper discusses some general aspects of mapping earth history.
