Broadbent, M.; Atkins, R.A.E. 1972 Seismic investigations in connection with the Huntly by-pass: June 1972. : . Report / Geophysics Division 80 11 p.
Abstract: Measurements have been made of the velocity of propagation of seismic P-waves in the indurated sediments exposed in quarries in the Taupiri Hills. A velocity of 1.2 km/s was recorded for deeply weathered red to yellow rock on a high bench in the Taupiri motorway quarry. Velocities of 1.8 to 2.4 km/s were recorded for unsaturated, relaxed, partially weathered rock on a bench in the Bitumix quarry, and velocities ranging from 2.5 to 4.5 km/s were recorded for hard blue rock in these and other quarries. Seismic refraction measurements were taken along thee lines, A, B, and C, over ridges of the Taupiri hills, where cuttings are proposed for a new highway. These give estimates for the depth below the corresponding ridge tops of rocks having velocities in excess of 2.5 km/s as about 26 m for lines A and B over the main ridge, and 12 m for line C over a subsidiary ridge (auth.)