Mookaite (Windalia Radiolarite Formation, Lower Cretaceous; Western Australia) 12 : 無料・フリー素材/写真
Mookaite (Windalia Radiolarite Formation, Lower Cretaceous; Western Australia) 12 / 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 | Mookaite from the Cretaceous of Western Australia. (~5.55 centimeters across at its widest)Mookaite is a silicified sedimentary rock from the Lower Cretaceous Windalia Radiolarite Formation, a succession of moderately deep marine siltstones and cherts that contain numerous microfossils of foraminifera, radiolarians, and coccoliths. Because this rock is hard, very fine-grained, and attractively colored, mookaite is valued as knapping material by flintknappers.The yellowish and reddish colors are from iron oxide impurities (limonite and hematite). |
| 撮影日 | 2019-01-28 16:29:36 |
| 撮影者 | James St. John |
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