Geology.
The Bulghah deposit lies within Pre-Cambrian rocks of the Arabian Shield, located in the western part of the Arabian Peninsula. Gold mineralisation is predominantly hosted by mesothermal gold veins, often associated with a 680Ma to 640Ma orogeny that amalgamated various terranes into the Arabian Shield. Gold is also associated with a 615Ma phase of diorite-granodiorite magmatism in the north-eastern Shield, and post 640Ma strike-slip faulting in the Najd fault system.

Gold mineralisation at Bulghah is hosted by a tonalite/diorite intrusion, which strikes roughly north-south. The tonalite/diorite intrusion is fault/shear bounded on the east and west sides, with the contacts dipping roughly 60° towards the east. The intrusion ranges from 200m to 500m wide, narrowing towards the south, and extends to the north and south for approximately 1,000m with a depth of about 450m. The intrusion is bounded to the east by meta-volcanics, primarily andesite, and by meta- sediments to the west. The meta-sediments include a distinct marble unit. The intrusion grades from tonalite to diorite in the southeast and northern parts of the project area. The diorite has a coarser texture, with hornblende and plagioclase phenocrysts in a light coloured matrix. The intrusion is cross- cut by numerous aplite dykes, which are sub- horizontal, and frequently have irregular geometries. The aplite dykes also occur on or near the contacts between the country rock and the intrusion.