Bediasites (Late Eocene, 35 Ma; southeastern Texas, USA) 1 : 無料・フリー素材/写真
Bediasites (Late Eocene, 35 Ma; southeastern Texas, USA) 1 / James St. John
| ライセンス | クリエイティブ・コモンズ 表示 2.1 |
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| 説明 | Bediasites from southeastern Texas, USA. (public display, meteorite museum at Odessa Impact Crater, Texas, USA)Large & small impacts have affected Earth since its formation 4.55 billion years ago. Compared with the intensely pitted and cratered Moon, Earth has relatively few preserved impact craters, because they have been destroyed by water & glacial erosion. Impact events are accompanied by tremendous amounts of heat, resulting in melting of much of the ejected pulverized bedrock at ground zero. The melted material cools quickly, and falls back to Earth in the form of impact splash glasses (a.k.a. tektites). Tektites are principally composed of amorphous silica (SiO2). Broken surfaces show a conchoidal fracture. Tektites from different impact events are given different names.Bediasites are black-colored impact splash glasses from southeastern Texas, USA. They form part of the North American Tektite Field, produced during the Late Eocene (35 million years ago) by the Chesapeake Bay Impact event (eastern seaboard of USA). Other tektites produced by this event include georgiaites and specimens recovered from Massachusetts, Cuba, Barbados, offshore New Jersey, and in the Pacific Basin.------------------------------See info. at:en.wikipedia.org/wiki/Bediasite |
| 撮影日 | 2007-08-27 16:11:55 |
| 撮影者 | James St. John |
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