The original data obtained from the reference line are computed and rotated to their real spatial position by a reorientation process in 3 steps.

The data are first plotted on a stereonet for each reference line respectively.

The second step consist of reprocessing of all the stereonet in order to place in a parallel orientation all the reference planes. After this operation, clear trends appear for tectonic and sedimentary planes.

In a third step, all data are reoriented in order to make the trends fit the diagraphic (BHTV, Dipmeter, FMI) and geophysical information.

The geological trends obtained above are subsequently compared to the information from the available geophysical documents.

This reorientation process is done only on well preserved core fragments, to reduce the uncertainty.

Such an approach leads to results, ranging into an interval of confidence of more or less 10° for the azimuths and more or less 5° for the dip values

STEREOGRAPHIC PROJECTION IN ORDER TO ORIENT STRUCTURES ON CORES USING BORE HOLE IMAGERY