Hf-W同位体の証拠は,初期の太陽系における急速な蓄積と微分化の証拠である
1Department of Geological Sciences, University of Michigan, Ann Arbor, MI 48109-1063 USA.
Science (New York, N.Y.)
|December 13, 1996
まとめ
太陽系内部の物体は,数百万年以内に急速に増加し,分化しました. 隕石から得られたトングステンの同位体データは,太陽系初期における素早い親体形成と金属分離を明らかにしている.
科学分野:
- 惑星科学 惑星科学
- 宇宙化学 (コスモケミストリー)
- ジオクロノロジー (Geochronology) について
背景:
- 太陽系内部の天体の収縮と微分の時間スケールは,流星同位体系が混乱しているため,依然として不確実である.
- ハフニウム-182 (182Hf) がトングステン-182 (182W) に崩壊すると,両方の元素の耐火性および不動性により,貴重なクロノメーターを提供します.
研究 の 目的:
- 初期の太陽系天体の増殖と微分の時間スケールを決定する.
- 182Hf-182Wの同位体系を用いて,正確な時系列測定を行う.
主な方法:
- IIA,IIIA,IVA,異常な鉄隕石,H,L,LLコンドライトを含む様々な隕石クラスにおけるボルンガムの同位体組成の分析.
- クロノメーターとして182Hf-182W崩壊システムの応用.
主要な成果:
- トングステンの同位体データは,研究された隕石の親体の急速な増殖を示しています.
- 証拠によると,金属分離は,太陽系形成の最初の数百万年以内に発生したことを示唆しています.
結論:
- 初期の太陽系は,急速な形成と分化プロセスを経験しました.
- 182Hf-182Wシステムは,初期の太陽系イベントの年代測定のための堅牢なツールです.
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