Discovery of Microbial-like Nanoparticles in the Red River Fault Zone and Its Tectonic Significance

Recently, microbial-like nanoparticles were firstly found in the granitic mylonite in the Red River Fault zone through Scanning Electron Microscopy observation. High-resolution Energy Spectrum analyses showed that the microbial-like nanoparticles contain about 10% carbon, which indicates they were formed by inorganic process rather than fungi. These findings, together with the XRD results revealed that the microbial-like nanoparticles were derived from the rock-forming minerals of the granite mylonite. Moreover, a large number of nanoparticles with various morphological features were observed and analyzed, and the formation mechanism and tectonic significance of microbial-like nanoparticles were discussed. The formation process of the microbial-like nanoparticles can be divided into four stages, which including the formation of granular nanoparticles when the rock fracture, the aggregation of granular nanoparticles to form the sheet-like nanoparticles, the process of tubular nanoparticles curled from sheet-like nanoparticles, and the shedding and aggregation of tubular nanoparticles. The later three formation stages of the microbial-like nanoparticles are the tectonic deformation stages of the nanoparticles, indicating multiple changes in the tectonic setting of the Red River Fault zone. The granular nanoparticles in the fault zone may be the smallest deformation products under the macroscopic tectonic stress field. The structure or deformation characteristics contain rich information of the macroscopic tectonic activities, which will shed lights on investigations of the traditional tectonic geologic issues. © 2021, Science Press. All right reserved.