Microcracks in Basalt and Tonalite at Friction     

Vettegren  V. I.  Ponomarev  A. V.  Mamalimov  R. I.  Shcherbakov  I. P.  Arora  K.  Srinagesh  D.  Chadha  R. K. 《Izvestiya Physics of the Solid Earth》2019,55(6):879-885

Izvestiya, Physics of the Solid Earth - Abstract—The growth rate and size of microcracks formed in the surface layer of basalt and tonalite (granodiorite) at friction are studied using...  相似文献   

Dynamics of fractoluminescence, electromagnetic and acoustic emissions upon impact on a granite surface     

V. I. Vettegren  V. S. Kuksenko  R. I. Mamalimov  I. P. Shcherbakov 《Izvestiya Physics of the Solid Earth》2012,48(5):415-420

The dynamics of fractoluminescence (FL), electromagnetic (EME) and acoustic emissions (AE) induced in a granite sample by a striker blow was studied. The impact causes strong irregular vibrations in the striker-sample system. About 900 ??s after the impact, the amplitude of these vibrations decreases approximately by a factor of 100. As granite possesses piezoelectric properties, the mechanical vibrations induce equally strong electromagnetic oscillations. FL arises about 60 ??s after the impact. The FL spectra contain the bands of ??1.9 and 2.6 eV, which means that under the impact, the SiOSi bonds are broken and SiO·free radicals and Si: centers are formed. FL appears as a series of flashes with a duration of ??10 ns. Each flash is assumed to correspond to the initiation of a microcrack. The linear sizes of the microcracks estimated from the intensity of the flashes and the velocity of elastic waves range from ??7 ??m to ??40 ??m, with an average of ??10 ??m. The microcracks are grouped in microseries with a duration of ??4??s, which causes modulation of strong AE oscillations by weak oscillations with a period of ??8 ??s. The formation of microcracks with a linear size exceeding ??30 ??m causes discontinuities in the time dependence of EME.  相似文献   

Study of nanocrystals in the dynamic slip zone     

G. A. Sobolev  S. M. Kireenkova  Yu. A. Morozov  A. I. Smul’skaya  V. I. Vettegren  V. B. Kulik  R. I. Mamalimov 《Izvestiya Physics of the Solid Earth》2012,48(9-10):684-692

Mineral composition is studied and a search to detect nanocrystals is conducted in the surface layers of slickensides formed due to dynamic slip in arkose sandstone. The infrared and Raman spectroscopy show that the slickensided layer is composed of nanocrystals of montmorillonite and anatase measuring ??15 nm and 3 nm, respectively. The crystalline lattice of the nanocrystals of montmorillonite is stretched by ??2.5% while the lattice of the nanocrystals of anatase is compressed by ??0.12%. Deeper than 3 mm below the slickenside surface, the sandstone contains nanocrystals of montmorillonite, beidellite and nontronite, quartz, plagioclase, and anatase. The nanocrystals of anatase have a linear size of ??8 nm. Their crystalline lattice is compressed by ??0.03%. It is supposed that montmorillonite in the slickensides was formed due to hydrolytic decomposition of silicates under friction of the fault planes sliding past each other.  相似文献   

Nanocracks upon Fracture of Oligoclase     

Vettegren  V. I.  Ponomarev  A. V.  Mamalimov  R. I.  Shcherbakov  I. P. 《Izvestiya Physics of the Solid Earth》2021,57(6):894-899

Izvestiya, Physics of the Solid Earth - Abstract—The spectrum of fractoluminescence (FL) upon fracture of the surface of oligoclase is obtained. The analysis of the spectrum has shown that...  相似文献