Transmission Electron Microscopy Analysis on Fault Gouges from the Depths of the Bairendaba Polymetallic Deposit, Inner Mongolia, China

摘要

In order to investigate the relationship of nanoparticles in fault gouge and the deposit, We analyzed the particles in deep fault gouge samples from the Bairendaba polymetallic deposit using high resolution transmission electron microscopy. The microscopic characteristics of the particles, including the morphology, size and the composition of elements, are the main factors. The results show that (1) Most particles in fault gouges are irregular polygons, oval-shaped or nearly spherical, and have rough edges or strong diffraction contrast, and the size range distributes in 50-400 nm for most particles. (2) The compositions of the such nanoparticles are mainly As-bearing, Si-bearing, Mo-bearing, Iron-oxide, Ti-Fe oxide and calcium carbonate particles. The results imply that gouge particles had great association with the concealed deposits. The elements of all particles would reflect the composition characteristics of the ore bodies and surrounding rocks of the depth, especially the distribution of Zn. The As-, Mo-and Ti-bearing particles also correspond to the components related to mineralization. Considering the particle characteristics and the ascending gas in earth interior (geogas theory), we thought that the nano-scale mineral particles must be widespread in the deep tectonic belts. Moreover, the elementary composition of the nanoparticles suggests that they may come from the mineralization and tectonic movement. Because of the good permeability of the tectonic belts, the mineral nanoparticles are more easily carried by "geogas," groundwater or other approaches to the earth's surface. We can use the method of collecting and analyzing the Nano particles in geogas, underground water, surface flora, for deep prospecting.