Abstract
The city of Dunedin, New Zealand, is situated on the eroded remnants of an intraplate volcano. The Dunedin volcanic rocks are part of the Waipiata Volcanic Field, which at 25 Ma began as small (≤ one km³) volcanoes widely spaced through the region. Sixteen million years ago, for reasons yet unknown, a much larger (> 100 km³), more explosive concentration of volcanism initiated in shallow seas at the site of Dunedin. A new collaborative research effort is being undertaken to identify the foreshadowing conditions of intraplate volcanism, understand palaeonvironmental conditions, the eruption sequence and magmatic evolution of the region and, to better constrain hazards from faulting and landslides through a better constrained volcano-stratigraphy. This will be the first updated regional approach to mapping the Dunedin volcanic stratigraphy since the classic work of Benson in the mid-20th century. The mapping is integrating new high precision LiDAR data, geomorphology, modern physical volcanology interpretations, onshore airborne geophysics, offshore seismic and magnetic surveys into a GIS supported by GeoSciML. The mapping is being supported by petrology, new high-precision Ar-Ar geochronology, whole rock and mineral isotopic and geochemical analysis and palaeomagnetic studies. These efforts build upon the detailed and significant work already undertaken by researchers and students. Combined, these data will provide the most complete picture of Dunedin volcanism so far. The project, which is currently underway, will produce a map sheet and accompanying monograph, as well as being available as a downloadable GIS package. Numerous supporting journal articles and student theses are also anticipated. The research will be applicable to sea-rise studies, hazard modelling for faults and landslides, understanding the causes for intraplate volcanism away from subduction or rifting at plate boundaries, or mantle plumes and what drives highly variable rates of magma generation in these settings.