The weathering of platinum-group element (PGE) deposits presents unusual problems, especially in the very active environment of lateritic weathering under tropical conditions. There is clear evidence of the destruction of platinum-group minerals (PGM) to form PGE oxides, or fine intergrowths between relict PGM and iron oxides or hydroxides, as an intermediate stage during weathering. The PGE released by weathering are transported in solution with the more soluble Pd species remaining in solution and travelling further than the less soluble Pt species. The presence of PGM in the laterite differing in mineralogy, mineral assemblage and size from those in the primary rock is difficult to explain, especially when they show secondary textures. Differing interpretations have created controversy. Are alluvial PGM derived unaltered from the primary rock where they are rare and, therefore, not encountered by standard petrographic examination? Is it possible that they could have developed in the laterite by some process that we do not yet fully understand? Some favourable genetic conditions have been outlined and debated. For more than 100 years authors have reported secondary ore textures and recently proposed a biogenic origin. Frank Reith and his co-workers provided evidence of a process involving metallophillic bacteria which, for the first time, demonstrates PGM growth in the laboratory under supergene conditions. Their work shows that a mechanism for supergene growth (‘neoformation’) can occur, which offers a new field of study of the appropriate Eh, pH, $f_{{\rm O}_ 2}$ conditions and organic and bacterial reactions that could permit supergene growth.

铂族元素（PGE）矿床的风化存在特殊问题，特别是在热带条件下红土风化非常活跃的环境中。有明显的证据表明，作为风化过程的中间阶段，铂族矿物（PGM）的破坏会形成PGE氧化物，或残留PGM与铁氧化物或氢氧化物之间的细微共生。由风化释放的PGE在溶液中运输，而溶解度较高的Pd物种则保留在溶液中，并且比溶解度较低的Pt物种传播得更远。很难解释红土中PGM的矿物学，矿物组成和大小不同于原始岩石中的PGM，尤其是当它们显示出次要质地时。不同的解释引起了争议。冲积型PGM是否保持不变，是从稀有的原始岩石中提取出来的，因此在标准的岩相学检查中是不会遇到的？它们是否有可能通过我们尚未完全理解的某些过程在红土中开发？一些有利的遗传条件已被概述和辩论。100多年来，作者报告了二次矿石的质地，最近提出了生物成因。弗兰克·瑞思（Frank Reith）和他的同事提供了涉及嗜金属细菌的过程的证据，这首次证明了超基因条件下实验室中PGM的生长。他们的工作表明，可以发生超基因生长（“新信息”）的机制，这为研究适当的Eh，pH，标准的岩石学检查没有遇到？它们是否有可能通过我们尚未完全理解的某些过程在红土中开发？一些有利的遗传条件已被概述和辩论。100多年来，作者报告了二次矿石的质地，最近提出了生物成因。弗兰克·瑞思（Frank Reith）和他的同事提供了涉及嗜金属细菌的过程的证据，这首次证明了超基因条件下实验室中PGM的生长。他们的工作表明，可以发生超基因生长（“新信息”）的机制，这为研究适当的Eh，pH，标准的岩石学检查没有遇到？它们是否有可能通过我们尚未完全理解的某些过程在红土中开发？一些有利的遗传条件已被概述和辩论。100多年来，作者报告了二次矿石的质地，最近提出了生物成因。弗兰克·瑞思（Frank Reith）和他的同事提供了涉及嗜金属细菌的过程的证据，这首次证明了超基因条件下实验室中PGM的生长。他们的工作表明，可以发生超基因生长（“新信息”）的机制，这为研究适当的Eh，pH，首次展示了超基因条件下实验室中PGM的增长。他们的工作表明，可以发生超基因生长（“新信息”）的机制，这为研究适当的Eh，pH，首次展示了超基因条件下实验室中PGM的增长。他们的工作表明，可以发生超基因生长（“新信息”）的机制，这为研究适当的Eh，pH，$ f _ {{\ rm O} _ 2} $可能允许超基因生长的条件以及有机和细菌反应。