Still a work in progress, there are problems with the bottom left (looks like exploding spikes caused by power fractals, however I believe the problem lies in the height-field itself, which was created in the function editor of Vue Infinite 2014 - eroded in World Machine, and then brought into Terragen. 
I have gone through each and every power fractal and have not found the answer yet.  Any ideas? 
Thanks for looking - Happy Fathers Day!  -Jerry