[ConservativeMind]

I don't understand how the weather is accreting minerals on the top of these mountains to make them taller, nor do I understand how the weather could subvert the bases of the mountains to force them upwards.

My take is that one of the above is happening, but frankly, this author does not make the situation clear.

[decimon]

I don't understand how the weather is accreting minerals on the top of these mountains to make them taller, nor do I understand how the weather could subvert the bases of the mountains to force them upwards.

What I get from this is that the Alps are somewhat analogous to an iceberg. They are neither growing nor shrinking due to any tectonic forces and so are floating on the soft mantle of the earth as does an iceberg in the sea.

As weather erodes, not accretes, the exposed mountains they lose weight. With lesser weight they are forced upwards as is an iceberg when it loses weight to melting.

If I have it right then this condition would be peculiar to the Alps. Most other mountain ranges would be experiencing different forces causing them to either shrink or grow.