Pressure-induced amorphization of albitic plagioclase in an externally heated diamond anvil cell

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Abstract

[1] High-pressure and high-temperature experiments of albitic plagioclase up to 41 GPa and 270 °C were carried out using an externally heated diamond anvil cell. Raman spectroscopy and transmission electron microscopy of the recovered samples revealed that the amorphization of albite was complete at ∼37 GPa and room temperature. The amorphization pressure at 170 °C was nearly the same as that at room temperature. In contrast, the pressure largely decreased to ∼31 GPa at 270 °C. In comparison with the amorphization pressure of albite in laboratory shock experiments, that in the present static compression experiments is significantly lower (>10 GPa) even at room temperature. This suggests that shorter pressure duration results in a lower degree of amorphization of plagioclase. The formation of maskelynite in shocked meteorites does not necessarily require the very high shock pressure (30–90 GPa) that was previously estimated on the basis of shock recovery experiments.

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