bos-sfo-sba278.JPG : 無料・フリー素材/写真
bos-sfo-sba278.JPG / dsearls
| ライセンス | クリエイティブ・コモンズ 表示-継承 2.1 |
|---|---|
| 説明 | A quarry carves greywacke out of the flank of San Bruno Mountain. The mountain is one of several terranes — three-dimensional hunks of landscape — that comprise San Francisco. It's made up largey of greywacke, which is a rock formed (in this case) from sandy sediments washing down into the trench through which the Farallon plate was subducted under the North American Plate for about a hundred million years. When that ended, a few dozen million years ago, and the trench boundary became the San Andreas Fault, the Pacific Plate (which had been following the Farallon) began to travel northwestward, carrying various terranes along with it. Meanwhile, the new seam formed by the fault turned trench into hills and mountains. One of those is San Bruno. |
| 撮影日 | 2006-09-23 14:20:59 |
| 撮影者 | dsearls , Santa Barbara, USA |
| タグ | |
| 撮影地 | |
| 露出 | 0.005 sec (1/200) |
| 開放F値 | f/8.0 |
| 焦点距離 | 57 mm |