NEW PALEOMAGNETIC EVIDENCE FOR THE RECENT ERUPTIVE ACTIVITY OF MT TARANAKI, NEW-ZEALAND

Egmont volcano is the most westerly expression of volcanic activity in the North Island of New Zealand and is located 180 km above a westward-dipping subduction zone. Lava flows from the main cone Taranaki, and a parasitic cone Fanthams Peak, were sampled for palaeomagnetic analyses. Palaeomagnetic directions obtained from lava flows mostly from the upper northeast flanks of the main cone and Fanthams Peak were compared with an already established palaeosecular variation curve for the region. The palacomagnetic evidence suggests that the lava flows covering the main peak were extruded during two eruptive phases. An older phase occurred between 2800 and 7000 years B.P. and a younger phase between 400 to 700 years B.P. Some of the eruptive activity of Fanthams Peak may have occurred during the same time interval as the emplacement of the lavas of the northeast flank of Taranaki.