GPLATES VISUALIZATION REVEALS MASSIVE GLOBAL PLATE REORGANIZATIONS: 140 MA-133 MA

Global plate motion models are useful tools for studying super continent cycles, tectonic suturing or rifting, and climate. Running these models can show previously unknown or not well understood phenomena occurring on the scale of millions of years. However, visualizing global scale changes can be difficult, especially if when large changes take place quickly. Therefore the visualization and analytical program GPlates was used to visually analyze a number of published plate motion models. These visualizations highlighted weaknesses in several plate motion models for time periods between 200 Ma and 100 Ma, thus, only two global plate motion models were used to analyze the entire time period between 200 Ma and the present. Both models show that around 140 to 139ma there was a massive shift in plate motion that continued until around 133ma. This shift shows up in the models as a near 90 to 120 degree flip in the velocity vector azimuth of the Farallon, Antarctic, East African, North American, Eurasian, North West African, East Gondwana, and South African plates. The greatest change in velocity was that of the Phoenix plate which saw a ~108% increase in velocity between 140 and 139ma. Because of the manner in which plate motion models are constructed, more analyses about which plates moved first is needed. However, given the short time frame in which these massive reorientations took place, we propose that there was a simultaneous or preemptive change in the mantle. Evidence for a change in the state of the mantle can be found in the eruption of numerous large igneous provinces and the Tamu Massif.