Your cited article is pretty brief, so a searched around more, and found (to my surprise
) that the origins history of the Andes Mountains is much more complex than I thought, and processes that formed one part of the chain may well be very different that the processes that formed other parts of the chain. Shamefully, I fell victim to an oversimplified vision of things.
I must concede, that tectonic uplift seems to be a very big part of the picture, in at least some areas of the Andes. It seems pretty hard to track down a good summary of what the relative contributions of volcanism and tectonic uplift were, in the big picture, in giving the mountains their great height. I still suspect that straight volcanism was sometimes the major component, but I may be wrong.
I'll now plead "too much ignorance", and drop any further discussion of the Andes formation. I await the opinion of a real expert on the genesis of the Andes.
Moose