It indeed looks nice, I like the waving layers. We'll just consider any vertical edges to be "faults" like real geologists, and make up a good story about it!

The faults in a singe layer are caused by switching "geomes". But I have a bug hidden somewhere causing whole layers to be shifted on chunk borders (see on the left). Vertical intrusions are planned and can already be seen in crust layer.

Also added a experimental vein generator based on quadratic and linear curves {P=(1-t)A+tB} {P=(1-t)^2A+2t(1-t)B+t^2C}. Could be used for hydrotermal veins.

Step size for the quadratic curve is approximated by {step=sqrt(2)/(|AB|+|BC|)}.