| Autor: |
Li-Wei Kuo, Steven A. F. Smith, Chien-Chih Chen, Ching-Shun Ku, Ching-Yu Chiang, Dennis Brown, Marianne Negrini, Wen-Jeng Huang, Tze-Yuan Chen |
| Jazyk: |
angličtina |
| Rok vydání: |
2021 |
| Předmět: |
|
| Zdroj: |
Scientific Reports, Vol 11, Iss 1, Pp 1-14 (2021) |
| Druh dokumentu: |
article |
| ISSN: |
2045-2322 |
| DOI: |
10.1038/s41598-021-01559-x |
| Popis: |
Abstract Cloud-to-ground lightning causes both high-temperature and high-pressure metamorphism of rocks, forming rock fulgurite. We demonstrate that a range of microstructural features indicative of high temperatures and pressures can form in fulgurites at the surface and in fractures up to several meters below the surface. In comparison to a granite reference sample collected from a borehole at a depth of 138 m, microstructures in both the surface and fracture fulgurite are characterized by: (i) the presence of glass, (ii) a phase transformation in K-feldspar with the presence of exsolution lamellae of plagioclase, and (iii) high residual stresses up to 1.5 GPa. Since this is the first time that fracture-related fulgurite has been described, we also carried out a 1-D numerical model to investigate the processes by which these can form. The model shows that the electric current density in fractures up to 40 m from the landing point can be as high as that on the surface, providing an explanation for the occurrence of fracture-related fulgurites. Our work broadens the near-surface environments in which rock fulgurite has been reported, and provides a detailed description of microstructures that can be compared to those formed during other types of extreme metamorphic events. |
| Databáze: |
Directory of Open Access Journals |
| Externí odkaz: |
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