On Friday, August 17, 2018 at 12:14:11 AM UTC-7, stargene wrote:
Is there an overarching link between the fact that, on the one
.....

Okay, I can understand how the closeness between mantle/plate
motion and lunar recession motion can be a coincidence. Nothing
suggests otherwise apparently. It does seem to me that a check
might be to compare their respective motion rates in the deep
geophysical past--Say, over two billion years or so--One would
somehow need to detect fossil plate-motion speeds, probably
using proxies. Additionally, could one reliably constrain lunar
recession speeds over the same intervals? Ie: If it then appeared
that the two different motions were close over the Earth's age,
it might suggest a coupling. But again, a plausible
coupling mechanism would be needed, to consider linkage to be
not merely circumstantial. I don't know if current geophysical
techniques would reasonably support such a search.

[[Mod. note -- Alas, I don't think we have experimental data giving
either of those rates at any time other than "now". So any estimates
for gigayears in the past are going to be heavily dependent on
theoretical models of the underlying dynamics.

There are then two possibilities:
* If you think the the models are basically ok, then it's obvious that
the plate-tectonic and lunar-orbit-evolution rates are independent.
* If you don't think the models are basically ok, then you probably
shouldn't trust their estimates of either rates in the distant past.
-- jt]]