Science. 1967 Mar 3;155(3766):1096-7. doi: 10.1126/science.155.3766.1096.
Polymerized hydrocarbons occurring in the gold-uranium conglomerates of the Witwatersrand System (South Africa) show deltaC(13) 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 10(9) years.
出现在威特沃特斯兰德体系（南非）金铀砾岩中的聚合碳氢化合物具有-22.4 到-32.8‰的 δC(13) 值，其同位素组成因此落入沉积有机碳的范围内。因此，该物质的有机来源似乎是非常有可能的。这一结论与这样一种模型一致，即在肯定早于 21.5 亿年的时代，就存在着有机进化和生物活动。
