Title: Development of Plate Tectonics Theory
http://www.infoplease.com/encyclopedia/science/plate-tectonics-development-plate-tectonics-theory.html
source 2 title: The Origins of Plate Tectonic Theory .
http://www.visionlearning.com/en/library/Earth-Science/6/The-Origins-of-Plate-Tectonic-Theory/65
Source 3: What is Plate Tectonics ? - Live Science: Scientific News ... www.livescience.com/37706-what-is-plate-tectonics.html Cached Jun 23, 2013 · Plate tectonics is the theory that Earth's outer shell is divided into several plates that glide over the mantle
Need I go on? It is a theory, the science isn't "settled".
I will agree that the metrics you cited are empirical measurements.
It’s not a theory.
I was taught by one of the people that developed it.
Cheers, ‘Pod.