Caratori Tontini, Fabio , Bassett, Dan, de Ronde, Cornel E. J., Timm, Christian and Wysoczanski, Richard (2019) Early evolution of a young back-arc basin in the Havre Trough. Nature Geoscience, 12 . pp. 856-862. DOI 10.1038/s41561-019-0439-y.

	Text s41561-019-0439-y.pdf - Published Version Restricted to Registered users only Download (2MB) | Contact
	Text 41561_2019_439_MOESM1_ESM.pdf - Supplemental Material Restricted to Registered users only Download (741kB) | Contact
Preview	Text (GEOMAR Pressemitteilung) pm_2019_44_plattenbewegung-NZ.pdf Download (136kB) | Preview
Preview	Text (GEOMAR Press release) pm_2019_44_plate-tectonics-nz.pdf Download (406kB) | Preview
Preview	Text (Post-Print) CaratoriTontiniNatGEO2019_HavreTrough_PostPrint.pdf - Accepted Version Download (3MB) | Preview

Abstract

Back-arc basins are found at convergent plate boundaries. Nevertheless, they are zones of significant crustal extension that show volcanic and hydrothermal processes somewhat similar to those of mid-ocean ridges. Accepted models imply the initial rifting and thinning of a pre-existing volcanic arc until seafloor spreading gradually develops over timescales of a few million years. The Havre Trough northeast of New Zealand is a unique place on Earth where the early stages of back-arc basin formation are well displayed in the recent geological record. Here we present evidence that, in this region, rifting of the original volcanic arc occurred in a very narrow area about 10–15 km wide, which could only accommodate minimal stretching for a very short time before mass balance required oceanic crustal accretion. An initial burst of seafloor spreading started around 5.5–5.0 million years ago and concluded abruptly about 3.0–2.5 million years ago, after which arc magmatism dominated the crustal accretion. The sudden transition between these different tectonomagmatic regimes is linked to trench rollback promoted by gradual sinking of the subducting lithosphere, which could have diverted the arc flux outside the region of seafloor spreading and induced the vertical realignment of surface volcanism with the source of arc melts at depth.

Actions (login required)

View Item