Plagioclase breakdown as an indicator for shock conditions of meteorites

Tomoaki Kubo, Makoto Kimura, Takumi Kato, Masayuki Nishi, Aiko Tominaga, Takumi Kikegawa, Ken Ichi Funakoshi

Research output: Contribution to journalArticle

47 Citations (Scopus)

Abstract

Shocked meteorites that were formed when their parent body underwent shock metamorphism often contain the mineral plagioclase either in an amorphous form or in its high-pressure phase. The peak pressures in shock metamorphism can be constrained by shock-recovery experiments that determine the amorphization pressures of plagioclase. However, in these experiments temperatures have been unrealistically low and timescales much shorter than those in natural events. Here we present in situ X-ray diffraction measurements of two kinds of plagioclase feldspar in conditions of increasing pressures and temperatures. We find that the amorphization pressure of plagioclase decreases with increasing temperature, suggesting that previous studies overestimated this parameter. We also found that the mineral jadeite forms first from amorphous plagioclase, whereas the nucleation of other minerals such as stishovite or garnet is significantly delayed. The occurrence of jadeite in shocked meteorites that do not contain stishovite can therefore be explained as a result of the crystallization kinetics. We conclude that the study of plagioclase breakdown can constrain the pressure-temperature-time history of shock events, and thus help to reconstruct the collisional history of asteroids in the early Solar System.

Original languageEnglish
Pages (from-to)41-45
Number of pages5
JournalNature Geoscience
Volume3
Issue number1
DOIs
Publication statusPublished - Jan 1 2010

Fingerprint

meteorite
plagioclase
shock metamorphism
stishovite
jadeite
mineral
temperature
parent body
history
asteroid
solar system
nucleation
indicator
feldspar
garnet
crystallization
experiment
X-ray diffraction
timescale
kinetics

All Science Journal Classification (ASJC) codes

  • Earth and Planetary Sciences(all)

Cite this

Kubo, T., Kimura, M., Kato, T., Nishi, M., Tominaga, A., Kikegawa, T., & Funakoshi, K. I. (2010). Plagioclase breakdown as an indicator for shock conditions of meteorites. Nature Geoscience, 3(1), 41-45. https://doi.org/10.1038/ngeo704

Plagioclase breakdown as an indicator for shock conditions of meteorites. / Kubo, Tomoaki; Kimura, Makoto; Kato, Takumi; Nishi, Masayuki; Tominaga, Aiko; Kikegawa, Takumi; Funakoshi, Ken Ichi.

In: Nature Geoscience, Vol. 3, No. 1, 01.01.2010, p. 41-45.

Research output: Contribution to journalArticle

Kubo, T, Kimura, M, Kato, T, Nishi, M, Tominaga, A, Kikegawa, T & Funakoshi, KI 2010, 'Plagioclase breakdown as an indicator for shock conditions of meteorites', Nature Geoscience, vol. 3, no. 1, pp. 41-45. https://doi.org/10.1038/ngeo704
Kubo T, Kimura M, Kato T, Nishi M, Tominaga A, Kikegawa T et al. Plagioclase breakdown as an indicator for shock conditions of meteorites. Nature Geoscience. 2010 Jan 1;3(1):41-45. https://doi.org/10.1038/ngeo704
Kubo, Tomoaki ; Kimura, Makoto ; Kato, Takumi ; Nishi, Masayuki ; Tominaga, Aiko ; Kikegawa, Takumi ; Funakoshi, Ken Ichi. / Plagioclase breakdown as an indicator for shock conditions of meteorites. In: Nature Geoscience. 2010 ; Vol. 3, No. 1. pp. 41-45.
@article{44a9e038d878467799f889ac7376ecf5,
title = "Plagioclase breakdown as an indicator for shock conditions of meteorites",
abstract = "Shocked meteorites that were formed when their parent body underwent shock metamorphism often contain the mineral plagioclase either in an amorphous form or in its high-pressure phase. The peak pressures in shock metamorphism can be constrained by shock-recovery experiments that determine the amorphization pressures of plagioclase. However, in these experiments temperatures have been unrealistically low and timescales much shorter than those in natural events. Here we present in situ X-ray diffraction measurements of two kinds of plagioclase feldspar in conditions of increasing pressures and temperatures. We find that the amorphization pressure of plagioclase decreases with increasing temperature, suggesting that previous studies overestimated this parameter. We also found that the mineral jadeite forms first from amorphous plagioclase, whereas the nucleation of other minerals such as stishovite or garnet is significantly delayed. The occurrence of jadeite in shocked meteorites that do not contain stishovite can therefore be explained as a result of the crystallization kinetics. We conclude that the study of plagioclase breakdown can constrain the pressure-temperature-time history of shock events, and thus help to reconstruct the collisional history of asteroids in the early Solar System.",
author = "Tomoaki Kubo and Makoto Kimura and Takumi Kato and Masayuki Nishi and Aiko Tominaga and Takumi Kikegawa and Funakoshi, {Ken Ichi}",
year = "2010",
month = "1",
day = "1",
doi = "10.1038/ngeo704",
language = "English",
volume = "3",
pages = "41--45",
journal = "Nature Geoscience",
issn = "1752-0894",
publisher = "Nature Publishing Group",
number = "1",

}

TY - JOUR

T1 - Plagioclase breakdown as an indicator for shock conditions of meteorites

AU - Kubo, Tomoaki

AU - Kimura, Makoto

AU - Kato, Takumi

AU - Nishi, Masayuki

AU - Tominaga, Aiko

AU - Kikegawa, Takumi

AU - Funakoshi, Ken Ichi

PY - 2010/1/1

Y1 - 2010/1/1

N2 - Shocked meteorites that were formed when their parent body underwent shock metamorphism often contain the mineral plagioclase either in an amorphous form or in its high-pressure phase. The peak pressures in shock metamorphism can be constrained by shock-recovery experiments that determine the amorphization pressures of plagioclase. However, in these experiments temperatures have been unrealistically low and timescales much shorter than those in natural events. Here we present in situ X-ray diffraction measurements of two kinds of plagioclase feldspar in conditions of increasing pressures and temperatures. We find that the amorphization pressure of plagioclase decreases with increasing temperature, suggesting that previous studies overestimated this parameter. We also found that the mineral jadeite forms first from amorphous plagioclase, whereas the nucleation of other minerals such as stishovite or garnet is significantly delayed. The occurrence of jadeite in shocked meteorites that do not contain stishovite can therefore be explained as a result of the crystallization kinetics. We conclude that the study of plagioclase breakdown can constrain the pressure-temperature-time history of shock events, and thus help to reconstruct the collisional history of asteroids in the early Solar System.

AB - Shocked meteorites that were formed when their parent body underwent shock metamorphism often contain the mineral plagioclase either in an amorphous form or in its high-pressure phase. The peak pressures in shock metamorphism can be constrained by shock-recovery experiments that determine the amorphization pressures of plagioclase. However, in these experiments temperatures have been unrealistically low and timescales much shorter than those in natural events. Here we present in situ X-ray diffraction measurements of two kinds of plagioclase feldspar in conditions of increasing pressures and temperatures. We find that the amorphization pressure of plagioclase decreases with increasing temperature, suggesting that previous studies overestimated this parameter. We also found that the mineral jadeite forms first from amorphous plagioclase, whereas the nucleation of other minerals such as stishovite or garnet is significantly delayed. The occurrence of jadeite in shocked meteorites that do not contain stishovite can therefore be explained as a result of the crystallization kinetics. We conclude that the study of plagioclase breakdown can constrain the pressure-temperature-time history of shock events, and thus help to reconstruct the collisional history of asteroids in the early Solar System.

UR - http://www.scopus.com/inward/record.url?scp=73449109516&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=73449109516&partnerID=8YFLogxK

U2 - 10.1038/ngeo704

DO - 10.1038/ngeo704

M3 - Article

AN - SCOPUS:73449109516

VL - 3

SP - 41

EP - 45

JO - Nature Geoscience

JF - Nature Geoscience

SN - 1752-0894

IS - 1

ER -