The geology and geochemistry of the Rhyacian Josephine gold deposit, Northwest Ghana

ABSTRACT

This paper focuses on the geology and geochemistry of the Rhyacian Josephine gold deposit in northwestern Ghana, where gold is primarily hosted in quartzites, with other lithologies observed, including granitoids, mafic intrusions, and gneisses. Four deformational events, D_JO0, D_JO1, D_JO2, and D_JO3, are observed. D_JO0 is synonymous with the primary preserved sedimentary crossbedding in the quarzitic rocks. Gold mineralization within the deposit is mainly associated with the D_JO1 NNW-trending dextral and steeply dipping sinusoidal shear zone. Gold occurs primarily as free gold and invisible gold within the lattices of the disseminated arsenopyrite along the shear foliation planes of the host rock. The ore body geometry is 15–40 m wide and strikes 800 m in the NNW direction. Silicification, sericitization, chloritization, and sulphidation are the main alteration assemblages associated with the gold mineralization zones within the Josephine deposit. Pathfinder elements for gold are stibnite, tellurium, sulphur, copper, silver, and Lead.

KEYWORDS:

• Deformation
• alteration
• mineralisation
• ore body
• Josephine deposit

Acknowledgements

The authors would like to express their gratitude to Azumah Resources Limited, the owners of the Josephine deposit, for granting them access to the tenement and drill cores. Additionally, the authors would like to extend their sincere appreciation to the Agate project for providing financial support for this research through student scholarship awards received by the first author in 2021 and 2022.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

Additionally, the authors would like to extend their sincere appreciation to the Agate project for providing financial support for this research through student scholarship awards received by the first author in 2021 and 2022.