| タイトル | Early Archean Spherule Beds-Confirmation of Impact Origin |
| 著者（英） | Shukolyukov, A.; Lugmair, G. W.; Byerly, G. R.; Lowe, D. R.; Kyte, F. T. |
| 著者所属（英） | Scripps Institution of Oceanography |
| 発行日 | 2000-01-01
2000 |
| 言語 | eng |
| 内容記述 | The oldest record of major impact events on Earth may be a number of early Archean (3.5 to 3.2 Ga) spherule beds that have been identified in the Barberton Greenstone Belt, South Africa. Several field, petrographic, and geochemical criteria distinguish these beds from typical volcanic and clastic sediments. These criteria include the wide geographic distribution of two beds in a variety of depositional environments, the presence of relict quench textures, absence of juvenile volcaniclastic debris within the beds, and extreme enrichment of Ir and other platinum group elements (PGE) as compared to surrounding sediments. Some researchers, however, argued for a terrestrial origin for spherule bed formation, possibly related to volcanism and gold mineralization. |
| NASA分類 | Geophysics |
| 権利 | Copyright |
| URI | https://repository.exst.jaxa.jp/dspace/handle/a-is/333052 |
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