Whenever I see relatively shallow, small boreholes, especially in clusters like this, I tend to assume it was for a paleomagnetics study. In this case, the rocks here have been through multiple stages of deformation, heating and alteration, so I doubt whoever did this was after data on the original, pristine rock. But there may be ways to unravel their paleomagnetic history- that is, what happened during the aforementioned "deformation, heating and alteration." On the other hand, there may be study techniques that use cores such as these to look at things other than their paleomagnetic history. Anybody know of other research methods that might result in such boreholes?