When you right click on a borehole in the Project Explorer you can copy the borehole by selecting the Duplicate command in the pop up menu. This will create a new borehole offset in x and y by 10% of the extents of the current data in GMS.
This command is useful when there is a large gap between boreholes. A new borehole with similar stratigraphy to neighboring boreholes can be placed in the gap and the contacts can be positioned as desired. Adding an artificial borehole or a "pseudo-borehole" in the gap gives the user more control over the shape of the TINs and solids created from the boreholes.
Related Links:
Creating and Editing Boreholes