Metallogenesis and Mineralization of Intraoceanic Arcs I: Kermadec Arc--Introduction

Abstract

The Kermadec intraoceanic arc marks the southernmost section of the Pacific Ring of Fire in the western Pacific region, a chain of mostly underwater volcanoes that stretches from north of Japan southward to New Zealand. The Kermadec arc, striking for 1,200 km from Monowai volcano to the North Island of New Zealand, represents the southern portion of the contiguous ~2,500-km Kermadec-Tonga arc (Fig. 1; de Ronde et al., 2003). The Kermadec arc is populated by almost 30 volcanic centers comprising single, large caldera or cone volcanoes, or less commonly, groups of relatively smaller cones (de Ronde et al., 2001, 2007; Graham et al., 2008). All of these volcanic centers lie to the west of the Kermadec Ridge in the southern and mid-parts of the arc—by up to 70 km in the case of Rumble II West—then merge with the Kermadec Ridge near the Kermadec islands around 30° S. The volcanoes then diverge away (westward) from the Kermadec Ridge in the northern reaches of the arc (Fig. 1). Fig. 1 Location map for the Kermadec arc and the various volcanoes referred to in the papers of this special volume. The Kermadec arc-Havre Trough system is made up, from east to west, of a number of tectonic elements, including the Kermadec Trench, the Kermadec Ridge, the Havre Trough (or Kermadec back arc), and the Colville Ridge. The volcanoes of the active arc front lie immediately west of the Kermadec Ridge in the southern and mid-parts of the arc, then merge with the Kermadec Ridge to the north. The underlying bathymetry (in shaded relief) is derived from the satellite altimetry grid of Smith and Sandwell (1997) with more up-to-date bathymetry over top, especially in the southern …