Coronation Hill geophysical downhole logging December 1986.

Abstract

Coronation Hill diamond drill holes DDH30 to DDH55 (excluding DDH50 and DDH53) and reverse circulation holes RC1 to RC5 were geophysically logged in June 1987: a total of 29 holes. Of these, complete logs were obtained from 20 holes, and useful partial logs were obtained from a further 5 holes. Radiometric values indicating zones of > 0.05% eU3O8 were found in 13 holes, but none of these indicated high grades, such as those in DDH29. While logging DDH45, the probe became stuck at 221m, and the cable separated from the probe. A drill rig was repositioned over the hole and used to recover the probe. The recovery was successful and cost effective, with minor damage to the probe. The report reminds of the dangers of probing 45degrees holes. The normal procedure of calibrating the probe at AMDEL in Adelaide was not yet completed at the time of writing.