Capricorn: Integrated, mineralogical, petrophysical and structural characterisation

The aim of this study was to examine the Abra deposit and the Horseshoe Range BIF in detail using a variety of petrophysical, mineralogical and structural methods. Petrophysical data collected included measurements of density, magnetic susceptibility, remanence and anisotropy of magnetic susceptibility (AMS). The results were assessed holistically in terms of the interrelationships between petrophysics, mineralogy, structure and their contribution to the geophysical expression of both deposits types.

The report contains 4 parts linked below.

For the Abra study, the petrophysical data were used to constrain a detailed 3-D magnetic model, which was be reconciled with Leapfrog interpolations of the drilling data available for the deposit. AMS results were used to delineate potential structural controls on mineralisation and/or enhancement of the mineralisation.

Integrated 3-D model of magnetic and density models for the Abra deposit relative to the magnetic anomaly and mineralised section.

For the Horseshoe Range study, mineralogy was quantified using SEM-TIMA data (i.e., mineralogy maps generated by a Tescan Integrated Mineral Analyser) and temperature susceptibility experiments were undertaken to: 1. Differentiate magnetite and hematite content (i.e., they cannot be discriminated using TIMA) and 2. Quantify the relative magnetisation contributed by magnetite, goethite, hematite and any other magnetic minerals present. AMS data was used to: 1. Assess the relative impact of magnetic anisotropy on modelling, and 2. Assess the deformation of the BIF Layers. Magnetic modelling was undertaken in order to confirm the findings of the petrophysical study, and furthermore provide insights into how best to differentiate mineralised from barren systems.