Hi there,
inspired by the spikes/spires experiments of Efflux and Volker Harun
i played around with that node-setup a little.Then i replaced the
get position and perlin noise by a power fractal and finally ended
up with the node-setup shown below.Of course there is much more to
explore,the possibilities are countless,but so far it seems to be
very versatile.See examples below.These variations were done by
changes in the second color adjust only (except for the 3 where
the noise has been changed additionally, "billows"and"perlin").
Hope it'll be useful,J.