Investigating the role of faults in fluid migration and gas hydrate formation along the southern Hikurangi Margin, New Zealand

This is a Preprint and has not been peer reviewed. The published version of this Preprint is available: https://doi.org/10.1007/s11001-020-09400-2.

This Preprint has no visible version.

Download Preprint
Downloads

Download Preprint

Authors

Jess Hillman , Gareth Crutchley, Karsten Kroeger

Abstract

The Hikurangi Margin off the east coast of the North Island (Te Ika-a-Māui) is a tectonically active subduction zone and the location of New Zealand’s largest gas hydrate province. Faults are internally complex volumetric zones that may play a significant role in the migration of fluids beneath the seafloor. The combined processes of deformation and fluid migration result in the formation of concentrated hydrate accumulations along accretionary ridges. It is not fully understood to what extent faults control fluid migration along the Hikurangi Margin, and whether deep-seated thrust faults provide a pathway for thermogenic gas to migrate up from sources at depth. Using 2D models based on seismic data from the region we investigated the role of thrust faults in facilitating fluid migration and contributing to the formation of concentrated gas hydrates. By altering permeability properties of the fault zones in these transient state models we can determine whether faults are required to act as fluid flow pathways. In this study we focus on two study sites offshore southern Wairarapa, using realistic yet simplified fault geometries derived from 2D seismic lines. The results of these models allow us to start to disentangle the complex relationship between fault zone structure, permeability, geometry, fluid migration and gas hydrate formation. Based on the model outputs we propose that faults act as primary pathways facilitating fluid migration and are critical in the formation of concentrated gas hydrate deposits.

DOI

https://doi.org/10.31223/osf.io/baj4x

Subjects

Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics

Keywords

marine, seismic, modelling, New Zealand, fluid migration, gas hydrate

Dates

Published: 2019-07-22 14:36

Last Updated: 2020-03-08 19:16

Older Versions
License

CC BY Attribution 4.0 International

Add a Comment

You must log in to post a comment.


Comments

There are no comments or no comments have been made public for this article.