Structural analysis and tectonostratigraphic evolution of the Reinga Basin, offshore northwestern New Zealand

Abstract

The complex polyphase tectonic evolution of the southwest Pacific, from Late Cretaceous to Neogene time, was recorded by the various offshore sedimentary basins of greater Zealandia. The Reinga Basin, offshore of northwestern New Zealand, exemplifies the interaction between the regional tectonic evolution and local variations in the mode of structural and sedimentary responses. While the principal phases of the Reinga Basin’s evolution are well-established, the spatial and temporal migration of active structural and sedimentary reactions to tectonic events has not been the focus of an in-depth analysis. This study seeks to elucidate the locus and timing of active deformation through the lens of tectonostratigraphic seismic interpretations and sequential structural restoration. An integrated workflow of deliberately chosen methods and software solutions yields a set of diagnostic seismic sections, and a representative depth-converted and restored section. By these methods, a conceptual model is proposed for the dynamics of the Reinga Basin’s sedimentary and structural response to an evolving tectonic plate reconfiguration. A systematic development of both extensional and compressional deformational features is proposed that embraces both the kinematic aspects of deformation as well as the causative tectonic forces. The result of this research is an enhanced understanding of the local response to regional tectonic events in the southwest Pacific. Economic significance may be found in the further constrained evolution of principal petroleum reservoir system components. Furthermore, this study compliments the established record of Reinga Basin research, offers a new and pragmatic interpretation of a well-studied seismic data set, and reduces the negative influences of interpretational uncertainty.