1990 Fiscal Year Annual Research Report

地球固体物質における衛撃波変成作用の研究

Research Project

Project/Area Number	02252213
Research Institution	Yamaguchi University
Principal Investigator	三浦保範山口大学, 理学部, 助教授 (10034729)
Co-Investigator(Kenkyū-buntansha)	加藤敏郎山口大学, 教養部, 教授 (40034714)
Keywords	衝撃変成石英 / 構造異常石英 / インパクトクレ-タ- / 高密度シリカ紘物 / 衝撃変成ラメラベイン / 隕石の衝突 / K / T境界の形成 / 恐竜の絶滅
Research Abstract	本研究で得られた新しい知見は次のようにまさめられ、国際論文として公表した。 (1)衝撃変成をうけた紘物粒子を超音波ディスクカッタ-で周囲をあまり破壊せずに選択的に取り出せ、X線・電子顕微鏡による構造解析が可能である。(2)超高速物質が衝突してできた北米・豪州のインパクトクレ-タ-と人工クレ-タ-中の衝撃変成石英紘物の物性変化を時間・空間解析した。衝撃波による超高圧の影響は、これまで高圧シリカ紘物の多量の残存によって実証されていたが、本研究では、瞬時に常圧の低温型石英紘物を多量形成されることが分かった。小数第3位に誤差がでるような高精度の単結晶X線構造解析実験から、その衝撃変成石英は、密度が水晶の標準デ-タより1%程度異常に高いことが分かった。(3)衝撃変成作用を受れた石英に衝撃ラメラベインが形成されているのは、超高圧下での高密度相が急激に減圧されて低密度相になるときの体積の差に相当することが分かった。地殼変動などのように地下深所で長時間かけて高温・高圧変成作用を受けた試料30個の石英には、このような衝撃変成ラメラベインは観察できなかった。(4)直径1km程度のアリゾナ・バリンジャ-隕石孔では、高密度シリカ紘物は、クレ-タ-のリムやセンタ-の地下深所に多い。レ-ルガン実験による直径約10cm程度の人工クレ-タ-では、クレ-タ-のリム壁面に高密度相や高温相が残存している。したがって、衝突による衝撃変成作用は衝突で外部に放出された中央部付近のエジェクタ-またはクレ-タ-のリム壁面に多量に残存していることが分かった。(5)恐竜や海生生物が大量に絶滅した白亜紀末期のK/T境界ができた理由は、本研究の実験結果から日本・欧米などのK/T境界に、高密度石英と衝撃変成ラレラペインをもつ石英が多産することが分かったので隕石等の地球外物質の超高速衝突によるものであると考えられる。

Research Products

(16 results)

All Other

All Publications (16 results)

[Publications] Miura Y.: "Evidence for shock wave effect of meteoritic impact." Shock Wave,An Internationa Journal (SpringerーVerlag). 1. 1-6 (1991)
[Publications] Miura Y.: "Shock meteamorphism of cosmic and terrestrial solidーstate meterials by shock wave." Symposium on Shock Waves,Japan(Tokyo)ー1990. 1. 279-284 (1990)
[Publications] Miura Y.: "Various formation processes of the KーT boundary sample from density variation of quartz minerals." Meteoritics(Meteoritical Society,UCLA,U.S.A.). 24ー4. 305-305 (1990)
[Publications] Miura Y.,Ashida T.and Okamoto M.: "Estimation of shockes pressure from density deviation of shocked quartz in impact crater and CretaceousーTertiary boundary." International Workshop on Meteoritic Impact on the Early Earth(LPI Contribution,LPI & NASA,U.S.A). 746. 34-35 (1990)
[Publications] Miura Y.and Imai M.: "Dendity deviation Of shocked quartz in the CretaceousーTertiary boundary." International Workshop on Meteoritic Impact on the Early Earth(LPI Contribution,LPI&NASA,U.S.A.). 746. 32-33 (1990)
[Publications] Miura Y.: "Estimation of impact sites from mafic contents of plagioclase in meteoritic crater." International Workshop on Meteoritic Impact on the Early Earth(LPI Contribution;LPI and NASA,U.S.A). 746. 30-31 (1990)
[Publications] Miura Y.: "Anomalous mineralogical data of shocked quartz grains from Colorado KーT bounday" EOS(Transactions,American Geophysical Union)(U.S.A). 71. 970-970 (1990)
[Publications] Miura Y.: "Estimation of supplied impact sites from density and composition of plagioclase feldspar." EOS(Transactions,American Geophysical Union)(U.S.A). 71. 945-945 (1990)
[Publications] Miura Y.: "Powder science of the Moon(1)" Powder Sciences and Engineering(Tokyo). 22(12). 56-60 (1990)
[Publications] Miura Y.: "Powder science of the Moon(2)" Powder Sciences and Engineering(Tokyo). 23(2). 69-74 (1991)
[Publications] Miura Y.: "On cosmic application of planetary sciences,life science and material sciences." 7th Space Utilization Symposium(Tokyo). 7. 271-276 (1990)
[Publications] Miura Y.: "Mineralogical data of shocked quartz grains from KーT bounday." Lunar and Planetary Science Conference XXI(NASA,U.S.A.). 21ー2. 793-794 (1990)
[Publications] Miura Y.: "Direct evidences of impact from shocked quartz grains in K/T bounday." 7th Internatuonal Conference on Geochronology,Cosmochemistry and Isotope Geology(Australia). 7. 67-67 (1990)
[Publications] Miura Y.: "Formation processes of shocked quartz grains from mineralogical data" 15th International Mineralogical Association(Beijing). 15. 96-97 (1990)
[Publications] Miura Y.: "Density and compositions of plagioclase between meteorites and impact craters" 15th International Mineralogical Association(Beijing). 15. 392-394 (1990)
[Publications] Miura Y.,Imai M.,Alvarez W.and Izett G.: "Mineralogical direct evidences of impact from shocked quartz grains in K/T bounday." 15th Symposium of Antarctic Meteorites. 15. 46-48 (1990)

1990 Fiscal Year Annual Research Report

地球固体物質における衛撃波変成作用の研究

Principal Investigator

三浦 保範 山口大学, 理学部, 助教授 (10034729)

Research Products

[Publications] Miura Y.: "Evidence for shock wave effect of meteoritic impact." Shock Wave,An Internationa Journal (SpringerーVerlag). 1. 1-6 (1991)

[Publications] Miura Y.: "Shock meteamorphism of cosmic and terrestrial solidーstate meterials by shock wave." Symposium on Shock Waves,Japan(Tokyo)ー1990. 1. 279-284 (1990)

[Publications] Miura Y.: "Various formation processes of the KーT boundary sample from density variation of quartz minerals." Meteoritics(Meteoritical Society,UCLA,U.S.A.). 24ー4. 305-305 (1990)

[Publications] Miura Y.,Ashida T.and Okamoto M.: "Estimation of shockes pressure from density deviation of shocked quartz in impact crater and CretaceousーTertiary boundary." International Workshop on Meteoritic Impact on the Early Earth(LPI Contribution,LPI & NASA,U.S.A). 746. 34-35 (1990)

[Publications] Miura Y.and Imai M.: "Dendity deviation Of shocked quartz in the CretaceousーTertiary boundary." International Workshop on Meteoritic Impact on the Early Earth(LPI Contribution,LPI&NASA,U.S.A.). 746. 32-33 (1990)

[Publications] Miura Y.: "Estimation of impact sites from mafic contents of plagioclase in meteoritic crater." International Workshop on Meteoritic Impact on the Early Earth(LPI Contribution;LPI and NASA,U.S.A). 746. 30-31 (1990)

[Publications] Miura Y.: "Anomalous mineralogical data of shocked quartz grains from Colorado KーT bounday" EOS(Transactions,American Geophysical Union)(U.S.A). 71. 970-970 (1990)

[Publications] Miura Y.: "Estimation of supplied impact sites from density and composition of plagioclase feldspar." EOS(Transactions,American Geophysical Union)(U.S.A). 71. 945-945 (1990)

[Publications] Miura Y.: "Powder science of the Moon(1)" Powder Sciences and Engineering(Tokyo). 22(12). 56-60 (1990)

[Publications] Miura Y.: "Powder science of the Moon(2)" Powder Sciences and Engineering(Tokyo). 23(2). 69-74 (1991)

[Publications] Miura Y.: "On cosmic application of planetary sciences,life science and material sciences." 7th Space Utilization Symposium(Tokyo). 7. 271-276 (1990)

[Publications] Miura Y.: "Mineralogical data of shocked quartz grains from KーT bounday." Lunar and Planetary Science Conference XXI(NASA,U.S.A.). 21ー2. 793-794 (1990)

[Publications] Miura Y.: "Direct evidences of impact from shocked quartz grains in K/T bounday." 7th Internatuonal Conference on Geochronology,Cosmochemistry and Isotope Geology(Australia). 7. 67-67 (1990)

[Publications] Miura Y.: "Formation processes of shocked quartz grains from mineralogical data" 15th International Mineralogical Association(Beijing). 15. 96-97 (1990)

[Publications] Miura Y.: "Density and compositions of plagioclase between meteorites and impact craters" 15th International Mineralogical Association(Beijing). 15. 392-394 (1990)

[Publications] Miura Y.,Imai M.,Alvarez W.and Izett G.: "Mineralogical direct evidences of impact from shocked quartz grains in K/T bounday." 15th Symposium of Antarctic Meteorites. 15. 46-48 (1990)

三浦保範山口大学, 理学部, 助教授 (10034729)