Tuesday, September 3, 2013

WOGE #401

After watching other players rapidly solve some very interesting challenges during the last month, I decided to try again with Brian's WOGE 400.  I saw that this was obviously a volcano located in an arid region of the northern hemisphere, yet there were farmland and large lakes nearby.  I loaded my Google Earth volcano placemarks (available here) and looked around in Mexico, then moved over to the middle east and quickly found Nemrut volcano.  As Brian's post suggests, this is a location with both a rich history geologically and an interesting human story.

For the next edition of WOGE, I will keep things arid.  This location is not famous, but the climate makes it possible to see the underlying geology very clearly. 
 Be the first to post a comment with the coordinates and a simple description of the geology seen (in this case what kinds of rocks) and you win the privilege of hosting the next WOGE.  If finding information about the geology is difficult, try doing a search for "geologic map of (country)" or the equivalent in the local language.  No Schott rule will be in effect this time. Visit Felix's blog for an explanation of that, as well as other rules and hints.


14 comments:

  1. I've updated the winninglist up to #400.

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  2. Wow... you've really stumped us on this one. I've found terrain that is ohhh so close. I've got to be in the right area, but I just can't find this exact spot.

    Brian

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  3. It's good to know that someone is out there looking. I suspect that if you were in the right area, you would have found the location already. If you are in the right hemisphere, maybe you are on the wrong continent. If you are on the right continent, maybe you are in the wrong hemisphere.

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  4. I GUESS the dark layer is volcanic over a light sedimentary layer? I didn't find it in Ethiopia and the wider surrounding areas (didn't look too thoroughly) and for scanning over the West US areas, I was too lazy.

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  5. I still haven't found the right continent, in fact I didn't know there were more to search (except Antarctica, but this looks too warn and not dry enough).

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  6. It looks like I should share a few hints:
    1) It is most likely that you just haven't checked the right area yet. Try pondering the implications of my previous comment some more.
    2) Because of the way Google Earth merges images to create large-scale views, you may need to move closer in order to pick out the location. If your scale bar shows 25 or 30km that should be close enough.
    3) Image date is (mostly) 8/5/03, but you won't see that displayed until you get very close.

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  7. Gentlemen, I give up. I have the location but I cannot explain the geology. The area is tectonialy complicated and this is something for the experts. I could explain somehow the wider area, where our location is. But I cannot find something about this brown, dark area which has a sharp corner to the light area. Maybe I found something, but lacking the deeper geological education, I do not understand it.
    For all the others, Matthew defines North America and South America as two different continents.

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  8. Of course they're different continents :-)
    I think that if no one else speaks up within a few hours you should go ahead and claim the win Felix. I am not geologist either, so I would be happy if you just told us what general types of rocks we are looking at and about how old. I don't want to hold up the game while the other players are searching Antarctica :-)

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  9. 12.045°, -71.474° Serrania de Jarara at the Guajira Peninsula Columbia. The dark rocks on our picture are of mesoproterozoic and Paleozoic origin.
    If you zoom out of our area, you can see two SE to NW trending Mountain ranges. The more eastern one is the Serrania de Jarara. The northern part of the Serrania is the former "Etapana Terrane" with greenschists, the middle part the "Jarara Terrane" and the southern part (our picture) are the old Mesoproterozoic rocks. On the peninsula Eclogites (possibly from the Etpana Terrane) can be found.


    The peninsula represents a record of the evolution of intra-oceanic subduction on arc-continent collision between the front of the Caribbean and the North and South America plates.

    (http://www.geologica-acta.com/pdf/vol0903a12.pdf)

    This would have been the perfect location for Péter Luffi, who always perfectly described such complicated areas.

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  10. Doesn't everyone think of Colombia when they see a desert?

    Congratulations Felix, your description of the geology is fine. I was mainly attracted to this area because the geology is not obscured by vegetation, dune fields, or deep shadows. However, as you say, it is very complex and finding information is not easy. In addition to the paper you cite, I was finally able to find one paper in English with a semi-comprehensible explanation of the sharp contrast seen in this image:

    "West, south and east of the Serrania de Jarara, the Siamana Formation, a 430 m thick Oligocene marine sequence of very fine and fine grained, calcareous and fosiliferous sandstones, lies non-conformably over the Etpana Metamorphic Suite".
    http://www.revistas.unal.edu.co/index.php/esrj/article/view/20991/28714

    So we have a sharp division between very, very old metamorphic rocks and much younger sedimentary ones. There is more information available in Spanish for those who are interested.

    http://www.bdigital.unal.edu.co/4038/1/194676.2010_pte_1.pdf
    About the Siamana Formation.

    http://www.academia.edu/3694226/2012-Lopez_and_Zuluaga._Neis_de_Macuira
    About the darker metamorphic rocks.

    We look forward to seeing what Felix will chose for the next challenge.

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  11. Woge#402 ist at http://woge-felix.blogspot.de/2013/09/where-on-google-earth-402.html

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  12. Wow... I wasn't even close!!!

    I found areas in Africa, Afghanistan, and China that were VERY similar - right down to the terrain color, mountain direction, imagery copyright, cloud 'feel', even cloud shadow direction.

    I feel good, though, that it wasn't in an area I looked at and simply missed it.

    Brian

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  13. I hope I didn't frustrate anyone too much by using a small and little-known desert. I was trying to give a hint by suggesting that if you were on the right continent you should change hemispheres. Only Africa and South America are located in both the northern and southern hemisphere. Changing from one to the other in Africa would not help much. However, South America has only a tiny desert in the northern hemisphere. I guess I should remember that this contest is for finding images, not solving riddles.

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  14. It didn't frustrate me. I found lots of interesting places along the way - some potential future WoGE's!

    Brian

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