Structure and structural development of the Havre Trough (SW Pacific)

Northeast of New Zealand the Pacific plate is obliquely subducted beneath the overriding Australian plate. Major differences appear in the oblique‐convergence‐driven structures that occur along the plate boundary. While strike‐slip component of convergence is accommodated in the forearc domain to the south at the eastern North Island margin, we here substantiate that at least part of the strike‐slip component is accommodated within the back arc Havre Trough to the north offshore New Zealand. New swath bathymetry and structural data collected in the Havre back arc domain show that the basin as a whole displays oblique to basin axis structures that allow considering the basin to be the loci of extensive tectonics associated with dextral displacement of the Kermadec Arc Block relative to the Australian plate. Therefore, where the two plates are oceanic, the oblique convergence between Pacific and Australian plates is partitioned at the subduction trench for its normal‐to‐trench component and at the rear of the Kermadec Arc Block for part or all of its along‐strike component where it is intimately associated with extensional rifting within the back arc domain. The kinematic pattern of Australian‐Pacific plate boundary northeast of New Zealand that straddles a limit between continental and oceanic lithosphere allows addressing the specificity of the structural development, the deformation distribution, and the assessment of movement components that occur in a back arc basin associated with oblique convergence.