Organic-rich microfossils produced by oil infiltration of hollow silicified bacteria: Evidence from the ca. 340 Ma Red Dog Zn-Pb deposit, Alaska

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The remarkable preservation of carbonaceous microfossils in Precambrian chert has been attributed to rapid silica precipitation enclosing original cellular carbon. However, while silicification of bacteria can preserve cellular morphology, in modern silicifying environments, organic molecules are rapidly destroyed after death, raising questions about the origin of carbon in ancient microfossils. Here, we show that carbonaceous matter in filamentous microfossils in chert from the Carboniferous Red Dog Zn-Pb deposit, northern Alaska, represents relicts of migrated oil. Black, carbonaceous microfossils are associated with chert stained brown by solidified oil surrounding hairline fractures. The black filaments contain thin carbon films (

Original languageEnglish
Pages (from-to)1107-1111
Number of pages5
Issue number12
Publication statusPublished - Dec 2019

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