36 research outputs found
ニワトリの羽性鑑別法の活用性向上を目指した遅羽遺伝子の構造および羽性形質の品種網羅的解析
内容の要約広島大学(Hiroshima University)博士(農学)Doctor of Agriculturedoctora
Lithologies Making Up CM Carbonaceous Chondrites and Their Link to Space Exposure Ages
Chondrite parent bodies are among the first large bodies to have formed in the early Solar System, and have since remained almost chemically unchanged having not grown large enough or quickly enough to undergo differentiation. Their major nonvolatile elements bear a close resemblance to the solar photosphere. Previous work has concluded that CM chondrites fall into at least four distinct space exposure age groups (0.1 Ma, 0.2 Ma, 0.6 Ma and >2.0 Ma), but the meaning of these groupings is unclear. It is possible that these meteorites came from different parent bodies which broke up at different times, or instead came from the same parent body which underwent multiple break-up events, or a combination of these scenarios
CM carbonaceous chondrite lithologies and their space exposure ages
第6回極域科学シンポジウム[OA] 南極隕石11月16日(月) 国立国語研究所 2階 講
CM Carbonaceous Chondrite Lithologies and Their Space Exposure Ages
The CMs are the most commonly falling C chondrites, and therefore may be a major component of C-class asteroids, the targets of several current and future space missions. Previous work [1] has concluded that CM chondrites fall into at least four distinct cosmic ray space exposure (CRE) age groups (0.1 million years, 0.2 million years, 0.6 million years and greater than 2.0 million years), an unusually large number, but the meaning of these groupings is unclear. It is possible that these meteorites came from different parent bodies which broke up at different times, or instead came from the same parent body which underwent multiple break-up events, or a combination of these scenarios, or something else entirely. The objective of this study is to investigate the diversity of lithologies which make up CM chondrites, in order to determine whether the different exposure ages correspond to specific, different CM lithologies, which permit us to constrain the history of the CM parent body(ies). We have already reported significant petrographic differences among CM chondrites [2-4]. We report here our new results