<p>This is a bedding plane, once horizontal, but geological forces have tilted it to the diagonal. The strata above have been eroded and washed into the sea, perhaps by a storm, leaving the ancient bedding plane exposed. Tilted strata are not unusual in very ancient rock formations.</p>

CC BY-SA 4.0
2019-11-14T20:54:03.443Z
2019-11-14T20:54:03.443Z
Michael Walsby
<p>The new Mac OS boasts a beautiful default desktop background with the western tip of Santa Catalina Island.  The rock formation in the foreground looks like it was sliced on the diagonal with a power tool, but I assume this uninhabited side of the island hasn't actually been altered.  What accounts for this smooth rock face?</p>

<p><a href="https://i.sstatic.net/3QPcD.jpg" rel="nofollow noreferrer"><img src="https://i.sstatic.net/3QPcD.jpg" alt="enter image description here"></a></p>

<geology><california>
What's the story of the shear face in the new Mac OS Catalina wallpaper?
ed94133
# What's the story of the shear face in the new Mac OS Catalina wallpaper?

(Asked by: username_0 on 2019-11-14)

The new Mac OS boasts a beautiful default desktop background with the western tip of Santa Catalina Island. The rock formation in the foreground looks like it was sliced on the diagonal with a power tool, but I assume this uninhabited side of the island hasn't actually been altered. What accounts for this smooth rock face?

[![enter image description here](https://i.sstatic.net/3QPcD.jpg)](https://i.sstatic.net/3QPcD.jpg)

**Tags:** geology, california


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## 1 answers

### Answer by username_1 on 2019-11-14. Score: 2 | Accepted answer

This is a bedding plane, once horizontal, but geological forces have tilted it to the diagonal. The strata above have been eroded and washed into the sea, perhaps by a storm, leaving the ancient bedding plane exposed. Tilted strata are not unusual in very ancient rock formations.


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