Like Martin says, a screen shot of the node tree would also be helpful…
One of the lines appears to be because of the joining of two rock formations… You see this in a few places already (the one just above the middle one and the one off to the right, for example) but on that one formation they just happen to form at a nearly perfectly matching point. It’s possible the other two lines on that one formation could be the same thing, but it’s really hard to tell just by looking at the image alone.
