Presentation Details
Pyrite Microtextural Evidence and Multimodal Microbial Mineralization Records in the Qingjiang Fossils
ID：159
View Protection：ATTENDEE
Updated Time：2025-05-21 16:50:00 Hits：191
Oral Presentation
Start Time：Pending（Asia/Shanghai）
Duration：Pending
Session：No Session »
No files
Abstract
The coevolution of microorganisms and minerals constitutes a pivotal research theme in understanding early life-environment interactions on Earth. Biomineral assemblages formed through such processes offer unique archives for reconstructing deep-time microbial community structures and metabolic networks. Framboidal pyrite, widely regarded as a hallmark product of microbial sulfate reduction in anoxic sedimentary settings (Wilkin & Barnes, 1997), remains contentious regarding microbial regulation of its crystal morphology, spatial distribution, and isotopic fractionation mechanisms.
This study investigates Naraoia fossils from the Early Cambrian Qingjiang Biota in South China, employing multi-scale microscopy and microspectroscopy to decode pyrite morphological and biogenetic features. Micromorphological analyses reveal intricate pyrite differentiation patterns: 4–6 μm spherical pyrites are dispersed within the matrix(Fig.1E), while large-scale aggregates at fossil-rock interfaces—indicative of persistent anoxic bottom-water conditions during deposition of the Shuijingtuo Formation—are categorized into three subtypes: (1) framboidal clusters composed of cubic-octahedral microcrystals (0.5–8 μm, 40%)(Fig.1G), (2) framboids dominated by cubic or octahedral cross-section microcrystals (5–15 μm, 55%)(Fig.1G), and (3) chain-like aggregates with biologically diagnostic architectures (5%).
Notably, chain-type pyrites exhibit two distinct configurations: (i) filamentous structures formed by linearly aligned microcrystals, formally designated as Qingjiangonema ((Fig.1F,Fig.1G),)(Cui et al., 2024), and (ii) the first-reported euhedral octahedral chains reaching up to 800 μm in length(Fig.1H). The microscale morphological precision of these chains surpasses the constraints of inorganic self-organization, strongly suggesting microbial mediation. Future studies integrating sulfur isotope microanalyses will further test the biogenetic hypothesis of chain-like pyrite formation.
References
Wilkin, R.T., & Barnes, H.L. (1997). Formation processes of framboidal pyrite. Geochimica et Cosmochimica Acta, 61(2), 323-339.
Cui, Y., Fu, D., & Dai, T. et al. (2024). The Cambrian microfossil Qingjiangonema reveals the co-evolution of sulfate reducers and oxidizing cable bacteria. Science Advances.
This study investigates Naraoia fossils from the Early Cambrian Qingjiang Biota in South China, employing multi-scale microscopy and microspectroscopy to decode pyrite morphological and biogenetic features. Micromorphological analyses reveal intricate pyrite differentiation patterns: 4–6 μm spherical pyrites are dispersed within the matrix(Fig.1E), while large-scale aggregates at fossil-rock interfaces—indicative of persistent anoxic bottom-water conditions during deposition of the Shuijingtuo Formation—are categorized into three subtypes: (1) framboidal clusters composed of cubic-octahedral microcrystals (0.5–8 μm, 40%)(Fig.1G), (2) framboids dominated by cubic or octahedral cross-section microcrystals (5–15 μm, 55%)(Fig.1G), and (3) chain-like aggregates with biologically diagnostic architectures (5%).
Notably, chain-type pyrites exhibit two distinct configurations: (i) filamentous structures formed by linearly aligned microcrystals, formally designated as Qingjiangonema ((Fig.1F,Fig.1G),)(Cui et al., 2024), and (ii) the first-reported euhedral octahedral chains reaching up to 800 μm in length(Fig.1H). The microscale morphological precision of these chains surpasses the constraints of inorganic self-organization, strongly suggesting microbial mediation. Future studies integrating sulfur isotope microanalyses will further test the biogenetic hypothesis of chain-like pyrite formation.
References
Wilkin, R.T., & Barnes, H.L. (1997). Formation processes of framboidal pyrite. Geochimica et Cosmochimica Acta, 61(2), 323-339.
Cui, Y., Fu, D., & Dai, T. et al. (2024). The Cambrian microfossil Qingjiangonema reveals the co-evolution of sulfate reducers and oxidizing cable bacteria. Science Advances.
Keywords
Cambrian; Qingjiang Biota; Framboidal pyrite; Qingjiangonema; Chain-like pyrite
Speaker
Zhaoyang Cao
Student 中国科学院地质与地球物理研究所Submission Author
All Comments
Important Date
-
Conference Date
Jun 10
2025
toJun 13
2025
-
Apr 15 2025
Draft paper submission deadline
Sponsored By
National Natural Science Foundation of China
Geobiology Society
National Committee of Stratigraphy of China
Ministry of Science and Technology
Geological Society of China
Paleontological Society of China
Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences (CAS)
Institute of Vertebrate Paleontology and Paleoanthropology, CAS
International Commission on Stratigraphy
International Paleontological Association
Geobiology Society
National Committee of Stratigraphy of China
Ministry of Science and Technology
Geological Society of China
Paleontological Society of China
Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences (CAS)
Institute of Vertebrate Paleontology and Paleoanthropology, CAS
International Commission on Stratigraphy
International Paleontological Association
Organized By
State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences (CUG, Wuhan)
Contact Information
- Yizhou Huang
- yi******@cug.edu.cn
- 186********
Previous Conferences
-
2025-06-10 China Wuhan
第五届国际地球生物学会议 -
2017-06-24 China Wuhan,China
The 4th International Conference of Geobiology
Submit Comment