Shock temperature measurements in Mg/sub 2/SiO/sub 4/ and SiO/sub 2/ at high pressures

Journal Article · Fri Feb 01 00:00:00 EST 1980 · Geophys. Res. Lett.; (United States)

DOI:https://doi.org/10.1029/GL007i002p00141· OSTI ID:5287012

Lyzenga, G A; Ahrens, T J

Temperatures in the high pressure shock state have been determined by messurement of optical radiation from pure samples of forsterite (Mg/sub 2/SiO/sub 4/), ..cap alpha..--quartz, and fused silica. Shock waves of known amplitude were produced by tantalum flyer impact using a two-stage light gas gun. Shock pressures in the ranges 150--175 GPa and 70--115 GPa for Mg/sub 2/SiO/sub 4/ and SiO/sub 2/ respectively were achieved, and temperatures in the range 4500--6800 K were measured. The observed temperatures in Mg/sub 2/SiO/sub 4/ are consistent with the occurrence of a shock-induced phase transition with a transition energy of approx.1.5MJ/kg. Measured Hugoniot temperatures versus pressure in both fused and crystalline SiO/sub 2/ shcoked to the stishovite regime suggest the occurrence of a previously unknown transition, beginning at pressures of approximately 107 GPa and 70 GPa for ..cap alpha..--quartz and fused quartz, respectively. The energies and temperatures appear to be consistent with the onset of melting of stishovite under shock loading.

• Research Organization: Seismological Laboratory, California Institute of Technology, Pasadena, California 91125
• OSTI ID: 5287012
• Journal Information: Geophys. Res. Lett.; (United States), Vol. 7:2
• Country of Publication: United States
• Language: English

Related Subjects

58 GEOSCIENCES
MAGNESIUM SILICATES
SHOCK WAVES
QUARTZ
SILICA
MINERALOGY
PHASE TRANSFORMATIONS
TEMPERATURE MEASUREMENT
ULTRAHIGH TEMPERATURE
ALKALINE EARTH METAL COMPOUNDS
CHALCOGENIDES
MAGNESIUM COMPOUNDS
MINERALS
OXIDES
OXYGEN COMPOUNDS
SILICATES
SILICON COMPOUNDS
SILICON OXIDES
580300* - Mineralogy
Petrology
& Rock Mechanics- (-1989)