Abstract
Studying mantle convection requires knowledge of how plates moved over
and subduct into the mantle. Therefore, relative plate tectonic
reconstructions are placed in a mantle reference frame. These use the
geological expressions of plate-mantle interactions and correlate these
to mantle structure or minimize plate motions that would cause friction
with the mantle under the null hypothesis that active horizontal flow in
the mantle is negligible. However, mantle reference frames based on
different plate-mantle interactions are different. This may be due to
model uncertainty, but may also hold meaningful geophysical signals. To
explore this, we first computed a reference frame, in 10 Ma steps, that
adheres to a ’tectonic rule’ that minimizes absolute total continent
motion. We estimate the uncertainty by assigning a ±5 Ma time window
to the 10 Ma intervals and find that the continent frame, or alternative
frames based on an alternative ’rules’, may provide meaningful results
for the last 350 Ma, but are unresolved before that time. With this base
frame, we predict hotspot tracks, kimberlite and large igneous provinces
eruption sites, net lithosphere rotation, trench kinematics, and true
polar wander, which are all mostly within plausible ranges. We introduce
this coupled frame as a Solid Earth Integrated Reference Frame (SEIRF)
that may be used (1) to aid interpretation of anomalous geodynamic
behavior; (2) to obtain novel constraints on mantle convection - the
SEIRF allows studying ’mantle kinematics’ in a plate tectonic reference
frame and (3) may serve to train 3D numerical models of solid Earth
dynamics.