File:Glen Canyon Park Chert Outcrop.jpg

From Wikimedia Commons, the free media repository
Jump to navigation Jump to search

Original file (2,504 × 2,008 pixels, file size: 2.17 MB, MIME type: image/jpeg)

Captions

Captions

Outcrop of Franciscan radiolarian chert in San Francisco, California

Summary

[edit]
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 location37° 44′ 19.18″ N, 122° 26′ 33.07″ W  Heading=270° Kartographer map based on OpenStreetMap.View this and other nearby images on: OpenStreetMapinfo

References

[edit]
  1. ↑ 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.
  2. ↑ Sloan, Doris (2006). Geology of the San Francisco Bay Region (University of California Press). ISBN 978-0520241268.
  3. ↑ 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

[edit]
w:en:Creative Commons
attribution share alike
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/TimeThumbnailDimensionsUserComment
current04:05, 16 April 2007Thumbnail for version as of 04:05, 16 April 20072,504 × 2,008 (2.17 MB)Easchiff (talk | contribs){{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= }}

You cannot overwrite this file.

There are no pages that use this file.

File usage on other wikis

The following other wikis use this file:

Metadata

This file contains additional information such as Exif metadata which may have been added by the digital camera, scanner, or software program used to create or digitize it. If the file has been modified from its original state, some details such as the timestamp may not fully reflect those of the original file. The timestamp is only as accurate as the clock in the camera, and it may be completely wrong.

Retrieved from "https://commons.wikimedia.org/w/index.php?title=File:Glen_Canyon_Park_Chert_Outcrop.jpg&oldid=844997629"