Late Quaternary movement on the Ohariu Fault, Tongue Point to MacKays Crossing, North Island, New Zealand

Timing of the most recent surface rupture event on the Ohariu Fault near Paraparaumu, New Zealand

“…yr BP. Figure 3 illustrates the radiocarbon age constraints on the last rupture event from these trenches in relation to those from other localities along the Ohariu Fault (Heron et al 1998). The combined best estimate for the most recent rupture event, of 1000-1050 cal.…”

“…Heron et al (1998). Note that the radiocarbon ages of Heron et al (1998) have been recalibrated using the same techniques as described in the caption of Table 1 and the calibrated ages are presented at 2o. Thus, they differ slightly from those in their fig.…”

“…Shaded grey line is our best estimate for the most recent surface rupture event. See Heron et al (1998) for their sample locations.…”

“…The total onland length of the Ohariu Fault is c. 70 km, and the average fault strike is 030-050°. Late Quaternary fault motion is predominantly dextral strike-slip, with an average horizontal slip rate of 1-2 mm/yr, and a single-event lateral displacement (Heron et al 1998). Previous trenching studies have constrained the most recent surface rupture event on the Ohariu Fault south of Porirua Harbour to between 150 and 1130 cal.…”

“…The onland trace of the Ohariu Fault extends northeastward from Tongue Point on the south Wellington coast, to just north of Waikanae (Fig. 1A) (Heron et al 1998;Begg & Johnston 2000). North of Waikanae, the Northern Ohariu Fault (Palmer & Van Dissen 2002) appears to be the along-strike continuation of the Ohariu Fault.…”