Carbon Isotope Composition of Carbonaceous Matter from the Precambrian of the Witwatersrand System

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Science  03 Mar 1967:
Vol. 155, Issue 3766, pp. 1096-1097
DOI: 10.1126/science.155.3766.1096


Polymerized hydrocarbons occurring in the gold-uranium conglomerates of the Witwatersrand System (South Africa) show δC13 values between —22.4 and —32.8 per mille, their isotopic composition thus falling into the range of sedimentary organic carbon. Accordingly, organic derivation of the material seems very probable. This conclusion is consistent with a model of the existence of organic evolution and biologic activity in times certainly older than 2.15 x 109 years.