Past relative plate motion between Africa and Eurasia resulted in the closure of the Neo-Tethys Ocean and had important tectonic as well as climatic implications. Due to the convergent nature of this plate boundary, the past motion history can only be quantified through the plate circuit linking Africa-North America-Eurasia through the Central and North Atlantic Basins. The existing plate kinematic models were created prior to the collection of new geophysical data and before updated plate kinematic models for these basins were calculated. Moreover, the existing plate kinematic models lack estimates of uncertainties and their calculated relative plate motion during the Cretaceous Normal Superchron (between approximately 124 and 83 Ma) is unconstrained, although a major plate reorganization is known to have taken place during this period of time. Here we present an updated plate kinematic model for Africa and Eurasia (and Arabia and Eurasia for the northeastern part of the plate) since 156 Ma. We computed the rotation parameters, including estimates of uncertainties, for 15 finite rotation poles. For the Africa-North America Plate pair, we computed the Mesozoic rotation parameters and identified two time markers that represent variations in the behavior of the geomagnetic field within the Central Atlantic magnetic quiet zones. Together with fracture zone locations, we constrain the rotation parameters for this critical period, when the Africa-Eurasia relative plate motion has changed from sinisterly-dominated to convergence-dominated motion. Overall, the location of our Africa-Eurasia rotation poles, for most of the studied period, differ significantly (up to 500 km) from the existing poles. Our plate kinematic model predicts that the Late Cretaceous convergence rates were twice as fast as previously estimated and that the plate kinematic behavior during the Cenozoic was remarkably different compared to the Mesozoic, having significantly smaller changes in relative plate velocities and directions.
|Title of host publication||American Geophysical Union, Fall Meeting 2019|
|State||Published - 2019|
- Solid-earth geophysics; 18