3D magnetotelluric-derived electrical resistivity models of the Vulcan IOCG prospect under thick cover, South Australia

DOI: DOI not verified.

Creators:
Ben Kay

Three-dimensional electrical resistivity models derived from magnetotelluric (MT) data across the Vulcan iron-oxide copper–gold (IOCG) prospect in South Australia. The models image conductive sedimentary cover, a low-resistivity haematite breccia zone, and a deeper vertical conductive structure interpreted as a fluid pathway. Two inversion variants are provided: a smooth model and a structurally constrained “tear” model incorporating a known basement interface. These models provide constraints on subsurface structure and fluid pathways relevant to mineral exploration beneath thick conductive cover.

3D perspective views of the smooth (top) and tear (bottom) resistivity models, highlighting differences in basement structure. Clipped resistivity values (30–60 Ωm) emphasise the vertical conductive feature and haematite breccia zone; the tear model better resolves structure at the top of basement consistent with drillhole and gravity constraints.

3D perspective views of the smooth (top) and tear (bottom) resistivity models, highlighting differences in basement structure. Clipped resistivity values (30–60 Ωm) emphasise the vertical conductive feature and haematite breccia zone; the tear model better resolves structure at the top of basement consistent with drillhole and gravity constraints.

Research Tags

Associated Publication

Magnetotelluric imaging of an iron-oxide copper gold (IOCG) deposit under thick cover
Ben Kay, Graham Heinson, Goran Boren, Ying Liu, Simon Carter, Gerrit Olivier, Tim Jones, Rebecca Abel, Lisa Vella, Louise McAllister

DOI10.1080/08123985.2024.2378132

Abstract

This dataset contains 3D electrical resistivity models derived from magnetotelluric (MT) data collected over the Vulcan iron-oxide copper–gold (IOCG) prospect, located ~30 km northeast of Olympic Dam, South Australia. The survey comprises 100 broadband MT sites on a 1 km grid across a 9 × 9 km area. Inversion of MT responses resolves three primary domains: (1) conductive sedimentary cover (~850 m thick), (2) a low-resistivity zone associated with haematite breccia beneath the cover, and (3) a vertically extensive conductive structure extending to several kilometres depth, interpreted as a pathway for mineralising fluids. Two model variants are included: a smooth inversion and a model incorporating a structural discontinuity (“tear”) at the base of the sedimentary cover, based on drillhole constraints. The models provide insight into lithospheric-scale fluid pathways and the geometry of IOCG mineral systems under conductive cover sequences.

Graphic abstract

Compute Tags

None specified.

Software

Software information not available.

Model Setup

Inversion mesh used for 3D MT modelling, including padding cells and a structural “tear” boundary at the base of the sedimentary cover. MT site locations are shown as black triangles; drillhole logs provide constraints on the tear depth. Mesh projection UTM Zone 54S.

Inversion mesh used for 3D MT modelling, including padding cells and a structural “tear” boundary at the base of the sedimentary cover. MT site locations are shown as black triangles; drillhole logs provide constraints on the tear depth. Mesh projection UTM Zone 54S.

Citation

See source repository for citation.

Licence

CC-BY-4.0

Funders

  • Geological Survey of South Australia
  • FMG Resources Pty Ltd