Miocene tuffs preserved in argillaceous sediment interbedded with lacustrine successions are commonly encountered throughout the Dinarides Lake System (DLS) in south-eastern Europe. In this contribution the volcanic glass degradation and co-genetic Mn-Fe precipitation were studied in a 14.68 Ma felsic tuff from DLS Livno-Tomislavgrad Basin. Microbial activity has been involved in both reactions thus adding the interest of revealing effects of biotic and abiotic processes taking place during tuff eogenesis. X-ray diffraction and electron microbeam analysis with energy-dispersive X-ray spectroscopy revealed the pitting or granular structures developed at glass rims along with smectite flakes protruding from a degrading glass. Mn-Fe mineralization emerges in the form of Mn-Fe coatings, an initial step to micronodule formation, where traces of biogenetic influence included a high content of phases rich in structural Mn (IV) (i.e., ranciéite and jacobsite) and presence of microbial microfossils. Co-genetic ties between glass degradation and Mn-Fe precipitation were established through the report of dioctahedral smectite formed out of altered glass; which then served as nuclei of the ongoing biotic and abiotic Mn-Fe mineralization. These processes manifest on a continuous involvement of microbial life in the course of eogenesis of pyroclastic material in lacustrine environments.

中文翻译：

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致密化作用是长丝玻璃中细菌介导的锰铁微结节生成的诱因（波斯尼亚和黑塞哥维那利夫诺-托米斯拉夫格勒古湖）

在东南欧的迪纳里德斯湖系统（DLS）中，普遍遇到了中新世凝灰岩，其保存在与湖相陆相序交叠的泥质沉积物中。在这一贡献中，在DLS利夫诺-托米斯拉格勒盆地的14.68 Ma长凝灰岩中研究了火山玻璃的降解和Mn-Fe共生沉淀。微生物活性已参与两个反应，因此增加了揭示凝灰岩形成过程中发生的生物和非生物过程影响的兴趣。使用能量色散X射线光谱仪进行的X射线衍射和电子微束分析显示，在玻璃边缘形成的点蚀或颗粒状结构以及从降解玻璃中突出的蒙脱石片状结构。Mn-Fe矿化以Mn-Fe涂层的形式出现，这是形成微结节的第一步，其中生物遗传影响的痕迹包括高含量的富含结构锰（IV）的相（即红锌矿和雅克贝石）和微生物微化石的存在。玻璃的降解与Mn-Fe沉淀之间的共生关系是由玻璃蚀变形成的八面体蒙脱石的报道建立的。然后成为正在进行的生物和非生物锰铁矿化的核心。这些过程表明，在湖相环境中，火山碎屑物质的新生过程中微生物生命的持续参与。玻璃的降解与Mn-Fe沉淀之间的共生关系是由玻璃蚀变形成的八面体蒙脱石的报道建立的。然后成为正在进行的生物和非生物锰铁矿化的核心。这些过程表明，在湖相环境中，火山碎屑物质的新生过程中微生物生命的持续参与。玻璃的降解与Mn-Fe沉淀之间的共生关系是由玻璃蚀变形成的八面体蒙脱石的报道建立的。然后成为正在进行的生物和非生物锰铁矿化的核心。这些过程表明，在湖相环境中，火山碎屑物质的新生过程中微生物生命的持续参与。