Postgraduate Profiles

Joanna Hodge

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Thesis: Structural Architecture, Hydrothermal Alteration and Fluid Characteristics in the Kalgoorlie-Kambalda Area, Western Australia

My research aims to evaluate and identify characteristic hydrothermal alteration and fluid flow during deformation, magmatism and mineralisation associated with major deformation events along the Boulder segment of the Boulder Lefroy fault zone to explain why some structures are so richly endowed with gold and others are apparently barren.

The main focuses of my research are to:

1) Assess the nature of the regional scale structures in the area.

2) Identify the characteristic hydrothermal, magmatic and metamorphic fluids associated with different tectonic, igneous and mineralising events.

3) Evaluate the P-T-X-t conditions of the hydrothermal fluids.

4) Compare and contrast mineralised and non-mineralised systems.

5) Develop genetic, structural and hydrothermal fluid flow models of the study area.

6) Develop a regional exploration model.

Why my research is important

The relationship between tectonic events, hydrothermal, magmatic and metamorphic fluids, and their associated alteration assemblages is poorly understood, as are the reasons some structures are richly gold-endowed while others are apparently barren.

By analysing the spatial and temporal distribution of hydrothermal alteration, and comparing the fluid and alteration characteristics of mineralised and non-mineralised areas, as well as assessing the potential contribution of porphyries to gold mineralisation, the critical factors controlling mineralisation can be evaluated, and questions as to why some structures are mineralised while others are not can be answered.

This research will allow the development of regional hydrothermal fluid-flow and, ultimately, exploration models, which will provide a valuable tool to the exploration industry in the quest for smarter, cheaper exploration. It will also contribute to the greater understanding of Archean orogenic lode gold mineralisation