Primary silica precipitate at the Precambrian/Cambrian boundary in the South Oman Salt Basin, Sultanate of Oman

An organic-rich laminated chert (silicilyte) consisting of up to 90% microcrystalline quartz that formed at the Precambrian–Cambrian boundary acts as a light-oil reservoir in the subsurface of the South Oman Salt Basin, Sultanate of Oman. Fully encased in salt domes, it was first discovered during the 1990's hydrocarbon exploration activities of Petroleum Development Oman. Because of the economic significance and the unconventional reservoir characteristics, there is great interest in understanding the origin of the laminated chert, its source of silica and mode of precipitation in an anoxic, sulphur-rich, stagnant and highly saline basin.