What Is This and How the Heck Did It Happen?

Posted by MontereyJohn (Salinas, California, United States) on 8 January 2009 in Miscellaneous and Portfolio.

I know next to nothing about geology, but I know enough to know this is really weird.

This formation is in the cliff face at Pomponio State Beach. The angle of the layers is true. The questions for me are, "1. How did the sedimentary layer end up between the two igneous/volcanic layers, and, 2. what force of nature caused this 45 degree uplift from the horizontal?" (I'm reasonably certain I would not have wanted to be around when the uplift occurred!)

Pretty cool to look at and and ponder the forces of nature at work.

Thanks for dropping by and sharing in the joy I take in this art of photography. Enjoy your visit, and if you have any comments or useful criticisms, please feel free to share them.

You can visit my web site at http://montereyjohnphotography.com/

vfxy Photoblogs | Listed on Photoblogs.org

Comments (4)

MontereyJohn from Salinas, California, United States

From My son the geology student! Thanks Will:

I'll take that one. But first, let me say that this is an awesome example of what I am about to explain. This is a photo many geology professors would like to have. What you have captured is an igneous intrusion known as a dike. Dikes usually occur between a fault (which is clearly visible here). These are not sedimentary layers, and it appears that your dike has occurred in granite. This was one mass of magma that cooled into one piece of igneous rock. The dike occurred post the formation of this igneous rock. The dike is slightly more mafic than the granite, and may actually be classified as dioritic gabbro. This shows that the granite insulated the magma in the fault causing it to cool slowly creating a darker igneous dike. This is all igneous and was all below ground at one point in time. Either it was raised up during a quake or a few quakes or ground had eroded away from above it, mass wasting, etc. We're talking millions of years. A great example!

The surface is weathered and if you hacked off a little bit I be you would find a much lighter color granite.

7 Jan 2009 7:20am

Lorraine from Gatineau, Canada

WOW, I just know it's beautiful...ah nature you can't beat it... and thank you WILL for this wonderful lesson, what a fantastic field you're in, you must be so excited by your dad's find...Way to go John! John Shoots and Will explains, great documentary :)

8 Jan 2009 10:43am

Viewfinder from Bradenton, United States

I was going to post exactly what Will did on this amazing phenomenon. Only I didn't know enough to even begin. Heh. But as I read his "take" on what happened, I started to remember just enough of my old "earth science" classes way, way back (probably before the dike formed) to think this sounded vaguely familiar and felt right. So bravo John, for finding and photographing this great work of God's creation. And to Will, for helping us better understand the mechanics of it.

8 Jan 2009 4:58pm

Laurie from New Jersey, United States

Well I am not going to pretend I understood all of that...but I will say that it is a beautiful example of the earths interesting past. It is fascinating. Thanks Will for the detailed explanation.

9 Jan 2009 5:30am

Add your comment ...

next day →

Canon EOS REBEL XT
1/250 second
F/7.1
ISO 100
75 mm