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Groundbreaking Research on Clay Particle Alignment During Sedimentation
Clay minerals fundamentally shape the Earth’s surface, predominantly residing in the sediments of lakes, rivers, and oceans. The characteristics of these materials are heavily dependent on the orientation of their microscopic particles. A team of researchers from Martin Luther University Halle-Wittenberg (MLU) has achieved a significant breakthrough by utilizing the European Synchrotron particle accelerator in Grenoble, France, to closely observe these processes for the first time.
Published in the journal Communications Earth & Environment, this study provides crucial insights into the structural dynamics of sediments. Understanding the formation of clay-rich deposits poses challenges due to their occurrence on often inaccessible seafloors and the minuscule size of clay particles, which typically measure only a few micrometers. Traditional microscopy techniques fall short in capturing the sedimentation of these particles effectively, as pointed out by Dr. Rebecca Kühn, a geoscientist at MLU and the lead researcher of the study.
The research team employed cutting-edge technology, specifically the synchrotron particle accelerator, to advance their observations. “This instrument allowed us to observe sedimentation in real-time,” said Professor Michael Stipp, a geologist at MLU.
During their experiments, researchers submerged water-filled cylinders containing sedimenting clay particles within the high-energy X-ray beam of the accelerator. This experimentation was conducted under various conditions, including both fresh and saltwater environments. The research team precisely measured how the particles aligned over time, resulting in vast data generation. To address the challenge of data evaluation, co-author Dr. Rüdiger Kilian from MLU developed a new evaluation method for this study.
The findings revealed that clay particles begin to align within the first few millimeters of sedimentation. “The particles adopt a certain orientation very early on in the boundary layer between the water and the sediment,” Kühn explained. This alignment continues to strengthen within the initial layers of sediment.
These results contradicted a prevailing hypothesis that suggested the alignment of clay particles is primarily dictated by the much thicker layers of sediment above them. According to Stipp, the team’s findings not only challenge this assumption but also contribute to a broader understanding of particle behavior during sedimentation.
Grasping how clay particles align is essential for various practical applications. “This alignment impacts diffusion and thermal properties in clays and claystones, which are significant for geothermal energy exploitation and the stability of host rocks in nuclear waste repositories,” Kühn noted.
More information: Rebecca Kuehn et al., Clay alignment takes place during early stages of sedimentation, Communications Earth & Environment (2024). DOI: 10.1038/s43247-024-01866-x
Citation: Clay minerals: Researchers observe for the first time how sediment particles align during deposition (2024, December 2) retrieved 2 December 2024 from https://phys.org/news/2024-12-clay-minerals-sediment-particles-align.html
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