Constraining regional scale fault architecture in the southern New England Orogen: integration of seismic, multiscale edges and surface mapping

Abstract

Regional scale fault structures are considered a first order control on hydrothermal ore systems. Recognition and delineation of such features is essential for search space reduction and project selection in exploration. The New England Orogen in northeastern New South Wales has significant potential for the discovery of new hydrothermal ore systems. However, limits to interpretation of broad scale geophysics in the region and limited exposure for ground-based mapping have hampered the recognition of the first order fault architecture in many areas. As part of the Geological Survey of New South Wales 3D mapping program, we aim to further the understanding of strike extensive and depth penetrative regional scale fault architecture in the southern New England Orogen. The workflow for constraining the regional 3D fault architecture involves integrating a limited number of deep seismic lines with broader gravity and magnetic wavelet-based multiscale edges. All the geophysical data sets are further constrained by the Geological Survey of New South Wales' seamless geology mapping and surface structural orientation data. The work to date demonstrates correlation between the lateral position of multiscale edges and their dip inferred from upward continuation, with steeper dipping structures interpreted in seismic lines. Strike orientations of edges, or systematic breaks in edges, are broadly consistent with structural orientations previously recognised in mapping, but often not at the true regional scale as suggested by edge continuity. Known hydrothermal ore systems in the southern New England Orogen display a strong correlation with the deeply penetrating edges.