Create a PF set to Perlin ridges. Change the scale to 1e+006 or something. Set the displacement to 0 and check "Apply low color" and "Apply high color". Rename it to "Mountain blendshader". This is your blendshader. Go to your alpine fractal and check "use blendshader". Next to the text box is a button. Click on it and go to the "Assign shader" menu. Select your "mountain blendshader". Tada.