Has my volcanic theory been disproven?

We generally know  how far to dig to get 13,000 years ago, and we look at that dirt layer an we find nano diamonds. Let us continue:

Scientific American: The discovery lends support to a theory first advanced last year in that some type of cosmic impact or impacts—a fragmented comet bursting in the atmosphere or raining down on the oceans—set off the more than 1,300-year cooling period in the Northern Hemisphere known as the Younger Dryas for the abundance of an alpine flower's pollen found during the interval.

Now, here on earth, they tell us that volcanoes make diamonds.   Remember my theory, ice melts, northern crust lifts, volcanoes spew, earth gets cold.  And, in general, the ice cycles connect to geology acting as a pump.  This is earth, huge quantities of water existing in three phases, gonna overwhelm earth, one way or the other.  I would expect the earth orbital wobble and the ice cycles would have co-adapted, given the sudden change in mass density imposed by a melt..

Here is the catch in my story.   For  some reason we had a partial melt, and the crust moved a bit slowly, and sealed. Some, but not enough volcanic activity.  We  got stuck in very hot.  Why did that happen? 

The 'error' happened 13,000 years ago.  If we had a geological partial equilibrium, then we got no volcano power.   But we got CO2 power, that is the thing.  Intensive research on dropping the capital and operating costs of algae farming.  That should give us a million years, enough time to figure out what kind of geology we want on earth.

I digress.  Is the nano diamond discovery real, and did they really come from space.  There is ongoing discussion, debate.  Things will settle.

But, at the same time we have had recent research advances in producing nano diamond at less the the extreme pressure assumed. This is one to watch.