Edwards, A.R.. 1971 Report on five stratigraphic holes drilled in North Otago, 1968. Lower Hutt: New Zealand Geological Survey. Report NZGS 49 19p.
Abstract: In May and June 1968 the Geophysics Division, DSIR made its Joy-Sullivan truck mounted rotary drill rig available to the Micropaleontology section, NZ Geological Survey to put down five stratigraphic holes in North Otago. The drilling was carried out by Mr J.R. Jonhnstone and the late Mr P.J. Quinn of the Geophysics Division. The holes were sited and logged by the writer. All holes were continuously cored where practicable and most cores were bagged at 1 foot intervals before being dispatched to the NZ Geological Survey, Lower Hutt where Dr N. de B. Hornibrook examined selected samples for Foraminifera to establish the immediate micropaleontological results. The first hole at Trig Z, Oriake produced only negative stratigraphical results and had to be revisited but the log is included for the sake of completeness. For most of the period drilling was carried out under extremely adverse weather conditions and the writer wishes to acknowledge the perserverance of the drillers in completing these holes under circumstances which made operations very unpleasant.