



Stishovite (rutile-type SiO2) is the archetype of dense silicates and may occur in post-garnet eclogitic rocks at lower-mantle conditions. Sound velocities in stishovite are fundamental to understanding its mechanical and thermodynamic behavior at high pressure and temperature. Here, we use plate-impact experiments combined with velocity interferometry to determine the stress, density, and longitudinal sound speed in stishovite formed during shock compression of fused silica at 44 GPa and above. The measured sound speeds range from 12.3(8) km/s at 43.8(8) GPa to 9.8(4) km/s at 72.7(11) GPa. The decrease observed at 64 GPa reacts a decrease in the shear modulus of stishovite, likely due to the onset of melting. By 72 GPa, the measured sound speed agrees with the theoretical bulk sound speed indicating loss of all shear stiffness due to complete melting. Our sound velocity results provide direct evidence for shock-induced melting, in agreement with previous pyrometry data.
Show More# | Filename | Description | Filesize |
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1 | READ ME.txt | 1.66 KB | |
2 | 18-2SH06 VISAR.csv | 412 KB | |
3 | 18-2SH13 PDV.csv | 28.6 KB | |
4 | 18-2SH13 VISAR.csv | 336 KB | |
5 | 18-2SH15 PDV.csv | 42.7 KB | |
6 | 18-2SH15 VISAR.csv | 544 KB | |
7 | 18-2SH16 PDV.csv | 35.6 KB | |
8 | 18-2SH16 VISAR.csv | 370 KB | |
9 | 17-2S33 PDV.csv | 29.7 KB | |
10 | 17-2S33 VISAR.csv | 1.01 MB | |
11 | 17-2S37 PDV.csv | 23.7 KB | |
12 | 17-2S37 VISAR.csv | 215 KB | |
13 | 18-2S14 PDV.csv | 60 KB | |
14 | 18-2S14 VISAR.csv | 737 KB | |
15 | 18-2S15 PDV.csv | 142 KB | |
16 | 18-2S15 VISAR.csv | 673 KB | |
17 | 18-2SH06 PDV.csv | 36.9 KB | |
18 | 18-2S13 VISAR.csv | 305 KB | |
19 | 18-2SH10 PDV.csv | 21.3 KB | |
20 | 18-2SH10 VISAR.csv | 275 KB | |
21 | 17-2S49 PDV.csv | 48.7 KB | |
22 | 17-2S49 VISAR.csv | 386 KB | |
23 | 17-2S50 PDV.csv | 52.3 KB | |
24 | 17-2S50 VISAR.csv | 210 KB | |
25 | 18-2S13 PDV.csv | 44.7 KB |