英国伦敦大学学院Shahab Varkouhi和Dominic Papineau报道了来自化学振荡反应和作为前寒武纪环境替代物的硅石葡萄状体。相关论文于2023年5月19日发表在《地质学》杂志上。

研究人员表明，葡萄状体保留了针状石英（具同心纹层，呈放射状排列）的自相似模式，这在生物建造的叠层石中没有记录。这些古老的分形及其组成模仿了化学振荡反应中的分形，意味着葡萄状体的沉淀是由有机物的非生物成岩降解推动的，随后变质为燧石。

据介绍，在这项岩相学和地球化学研究中，研究人员在南非巴伯顿和加拿大冈弗林特的前寒武纪硅质岩中识别出了不同的石英晶胞，包括圆形-同心状、双晶、柱状、波状和叠层石装结构，以及类似几何形状和尺寸的同步生物模式（丝状特征和叠层石）。

附：英文原文

Title: Silica botryoids from chemically oscillating reactions and as Precambrian environmental proxies

Author: Shahab Varkouhi, Dominic Papineau

Issue&Volume: 2023-05-19

Abstract: In this petrographic and geochemical study, we differentiated diverse quartz botryoids, including circular-concentric, twinned, columnar, wavy, and stromatolite-like structures versus synchronous biotic patterns of similar geometry and size dimensions (filamentous traits and stromatolites) in Precambrian cherts of Barberton, South Africa, and Gunflint, Canada. The botryoidal habits explored retained self-similar patterns of radially aligned acicular quartz with concentric laminae, which are not documented in biologically built stromatolites. These ancient fractals and their composition imitate those in chemically oscillating reactions, implying that the precipitation of botryoids was fueled by abiotic diagenetic degradation of organic matter and subsequently metamorphosed into chert.

DOI: 10.1130/G50948.1

Source: https://pubs.geoscienceworld.org/gsa/geology/article-abstract/doi/10.1130/G50948.1/623574/Silica-botryoids-from-chemically-oscillatingredirectedFrom=fulltext