Tectonic clock?

https://archaeologynewsnetwork.blogspot.com/2017/02/earth-probably-began-with-solid-shell.html#79uFx3D6eodjY5SH.97

Earth's tectonic plates - how ancient?

Note: 12 plates subdivide Earth at equator, with one additional south pole plate. (I modified the map, adding the equatorial numbers. Click to enlarge)