A mining industry leader in Guyana, Barry Kevin O ‘Rourke oversees the extraction of precious minerals and metals for S.A.B. Mining. Focused on gold production, Barry Kevin O ‘Rourke has an in-depth knowledge of geologic formations, such as placer deposits.
The product of primary rock erosion, placer deposits contain a wide range of compacted sediment. Through wind, river, ocean action, and surface weathering, materials are transported from a source to deposits. They then undergo sedimentary processes that involve gravity separation and the accumulation of valuable minerals in specific areas.
Minerals that become concentrated in placer deposits have high specific gravities (heavier than quartz) and are erosion and weathering resistant. Among the most common are platinum, gemstones, zircon, and gold. They tend to group when surrounding rock erodes. When transported by natural forces, they also concentrate in depressions and river bends, where water speed changes. Areas of significant placer deposits include river deltas and coastal hills and lagoons.
