Other
Scientific paper
Apr 1994
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1994georl..21..721p&link_type=abstract
Geophysical Research Letters (ISSN 0094-8276), vol. 21, no. 8, p. 721-724
Other
3
Compression Loads, Impact Loads, Impact Melts, Metamorphism (Geology), Shock Loads, Sliding Friction, Spinel, X Ray Analysis, Aluminum Oxides, Magnesium Compounds, Magnesium Oxides, Meteoritic Composition, Scanning Electron Microscopy, Single Crystals, X Ray Diffraction
Scientific paper
The physics of mineral grain sliding, which occurs upon dynamic compression of rocks, is investigated by shock loading single crystals of corundum (Al2O3) and periclase (MgO) in contact obliquely in impact experiments. Energy dispersive X-ray analysis and X-ray diffraction studies of samples recovered from 26 - 36 GPa, 800 ns experiments indicated that under certain conditions a spinel phase of composition MgAl2O4 and thickness less than or equal to 20 microns was produced at the interface between the two crystals. Although the computed shock (continuum) temperatures were below those necessary to melt the initial oxides, the spinel nonetheless appears to have formed as a result of localised melting, via grain boundary sliding friction, followed by rapid quenching. Scanning electron microscopy (SEM) revealed some evidence for such melting. Moreover, the timescale of the experiments is too short for solid state diffusion (during the shock state) to explain the observed spinel thickness, although defect enhanced solid state diffusion, subsequent to loading and unloading, remains a possibility. The results also reinforce other recent observations and theories of heterogeneous deformation in minerals.
Ahrens Thomas J.
Potter David K.
No associations
LandOfFree
Shock induced formation of MgAl2O2 spinel from oxides does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Shock induced formation of MgAl2O2 spinel from oxides, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Shock induced formation of MgAl2O2 spinel from oxides will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1257086