Abstract

ABSTRACT Auriferous vein samples of the Angolan M’Popo deposit were characterized by a combination of 2D microscopy and 3D computed tomography (CT) in order to visualize and assess the gold distribution and gold morphology in in situ high-grade gold ore. The 0.1–2.4 m wide hydrothermal quartz veins in the Mesoproterozoic M’Popo granitic complex are composed mainly of quartz and pyrite, minor other sulfides and (visible) gold. The favourable X-ray attenuation/density contrast within this mineral assemblage allows delineation of the gold particle fraction so that gold particles of <0.01–19.95 mm³ in volume have been identified. Statistical analysis reveals that the bulk (∼99.98%) of all gold particles belong to the smallest volume classes (≤0.02 mm²) while large particles (>0.5 mm³) are few. The contrast between rounded, compact smaller particles and branched larger ones is clearly expressed in the CT reconstructions while transitions between these reflect a likely continuum in gold mineralization.

Full Text
Published version (Free)

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call