I found afew new fragments in the caves around the orb vallis.  they look like debt-bonds and they can be found where you can find torids. of course not all of them can be found where torids are, at least I don't think they can be, but looking around with a codex scanner will make finding them a lot easier, they're large and easily seen through walls.  I'm really bad at circling things I know. hope you can find more than I have so far, they're a lot by the looks of it, a whole lot.