Size of this preview: 748 × 600 pixels. Other resolutions: 299 × 240 pixels | 599 × 480 pixels | 958 × 768 pixels | 1,277 × 1,024 pixels | 2,504 × 2,008 pixels.
Original file (2,504 × 2,008 pixels, file size: 2.17 MB, MIME type: image/jpeg)
 | This is a file from the Wikimedia Commons. Information from its description page there is shown below. Commons is a freely licensed media file repository. You can help. |
Summary
| Description |
English: Roadcut revealing Franciscan chert rock, Glen Canyon Park, San Francisco, California.[1] This type of chert contains the skeletons of innumerable radiolarian creatures. It is a sedimentary rock, and the visible layering is due to the occasional inclusion of shale layers as the rock was deposited over millions of years.[2] The shale weathers more rapidly than the predominant chert, so the weathered rock looks like a stack. The remarkable folding of the stacked layers indicates the tectonic forces on this rock in this past, which warped the original planar layers into the fantastic shapes they now present. The road in the foreground is O'Shaughnessy Boulevard, which was constructed around 1935. This roadcut presumably dates from that time.[3] |
| Date | |
| Source | Own work |
| Author | Eric A. Schiff |
| Camera location |   | View this and other nearby images on: OpenStreetMap |  |
|---|
References
- ↑ Wahrhaftig, Clyde (1984) A streetcar to subduction and other plate tectonic trips by public transport in San Francisco, American Geophysical Union, pp. 29−32 ISBN: 9780875902340. See figures 24 and 25 in particular.
- ↑ Sloan, Doris (2006). Geology of the San Francisco Bay Region (University of California Press). ISBN 978-0520241268.
- ↑ San Francisco Recreation and Parks Department, "Significant Natural Resources Areas Management Plan," section 6.3 "Glen Canyon Park and O’Shaughnessy Hollow," (Final Draft Plan, February, 2006). This section contains several detailed maps on "Soils, Land Features, and Trails," "Vegetation," and "Sensitive Species and Bird Habitat." Retrieved February 3, 2007.
Licensing
This file is licensed under the Creative Commons Attribution-Share Alike 2.5 Generic license.
Attribution: Eric A. Schiff
- You are free:
- to share – to copy, distribute and transmit the work
- to remix – to adapt the work
- Under the following conditions:
- attribution – You must give appropriate credit, provide a link to the license, and indicate if changes were made. You may do so in any reasonable manner, but not in any way that suggests the licensor endorses you or your use.
- share alike – If you remix, transform, or build upon the material, you must distribute your contributions under the same or compatible license as the original.
File history
Click on a date/time to view the file as it appeared at that time.
| Date/Time | Thumbnail | Dimensions | User | Comment | |
|---|---|---|---|---|---|
| current | 04:05, 16 April 2007 | | 2,504 × 2,008 (2.17 MB) | Easchiff | {{Information |Description=Outcrop of Franciscan chert rock, Glen Canyon Park, San Francisco, California. |Source=self-made |Date=April 15, 2007 |Author= Eric A. Schiff |other_versions= }} |
File usage
The following 2 pages use this file:
Global file usage
The following other wikis use this file:
- Usage on de.wikipedia.org
- Usage on fr.wikipedia.org
- Usage on la.wikipedia.org
- Usage on zh.wikipedia.org
