Where on (Google) Earth #183

A post by Anne JeffersonI won the Where on (Google) Earth contest #182, hosted by Dr. Jerque at Geologic Frothings, by correctly identifying the location near Aktash, Altai Republic, Russian Federation. At that spot, some intriguing geomorphic stuff happened once upon time. More specifically, starting in these mountains, spectacular Pleistocene ice-dam failure megafloods raced across the Asian continent eventually reaching the Caspian, Black, and Mediterranean seas. Discharge from these floods is estimated to rival, or even exceed, the Missoula Floods. The location Dr. Jerque put in the spotlight is close to one of the ice dams, has some absolutely spectacular ripple fields, and is just upstream of an amazing gorge created by water rushing up to 45 m/s (162 km/hr, 100 mi/hr). There’s a really nice write-up of the floods, with on-the-ground photos, that can be found here.
Having just searched out one of the most jaw-droppingly powerful geomorphic spots on Earth, I’ve opted to go for something a bit more subtle for Where on (Google) Earth #183. Nonetheless, I think there’s something geo-interesting going on in this image. The eye altitude here is ~15 km and the vertical exaggeration on my browser was set to 2.
Click the image for a larger version.
First person to identify the latitude and longitude of the image, give a place name, and take a decent stab at why it might be interesting gets the honor of hosting the next round of the game. If you are not a blogger, you can still play, win, and then designate the blogger of your choice to host your image and the next round. I’m invoking the Schott Rule (sorry, Ron), which means that you need to wait one hour after the post time to answer for each Wo(G)E round you’ve won in the past.

Categories: by Anne, outcrops
Tags: , ,

Comments (13)

  1. Approximately -37.527 144.44
    Near Bullengarook, about 35 miles NW of Melbourne, Australia.
    Found reference to this posted in a newsgroup, so I thought I’d see how I do.
    Never done this before and don’t have a blog…. but it was fun.

  2. Congratulations Brian! Very nicely done. Would you care to take a stab at what might be geologically interesting about this place? (If not, perhaps we can recruit some other readers to help you out.)
    As the winner of the WoGE, you get to pick the next mystery location, and, since you don’t have a blog, you can pick the geoblogger of your choice to host the image for you.

  3. Hmmmm…my geology knowledge is rather sparse. I do have a hobby in seismology, though.
    But, I was quite surprised that Bullengarook is not in a valley, but on top of a ridge. That would not have been apparent without Google Earth’s 3D views. Looking at the topography it reminds me of places like Bryce Canyon and Grand Canyon. That is, a place where a river has cut through a region of uplift. Although, this is on a much smaller scale. I guess I’ll just have to sit back and listen to the experts.
    My knowledge of Australian geology and geomorphology just isn’t as good as I am with my back yard of Southern California.
    As for picking the next location, what are the rules?

  4. Chris Rowan says:

    Based on my knowledge of my co-bloggers interests, I worked out what this was without having any idea where it was: thanks to Brian, I have been able to confirm my hypothesis. But I’ll not share until someone else a chance to chime in.

  5. Kyle House says:

    At first glance it looked a bit like a valley swamped with sediment. Now I know from Brian and Google Earth that it is not a valley. Now, has the aroma of inverted topography or preferential exhumation / preservation of a resistant bed. Not a lava flow, though (?). Anxious to know.

  6. Clayton Summers says:

    A limestone cap, perhaps? It looks like there may some sinkhole lakes?

  7. Edward says:

    Gold, mate. Heaps of gold, mate.

  8. Ron Schott says:

    What at first appear in the map view to be some humongous megaripples (just left of center, in the top half of the image) appear upon further review low-level flyovers to be just some sort of atmospheric (cloud) artifact on the satellite imagery.
    The only other thing I could find about the geology of the area was a Wikipedia description of the geology of Lerderderg Gorge, located in the southwest quadrant of this image: The Lerderderg Gorge is cut by the Lerderderg River into the blocks of the Rowsley, Greendale and Coimadai Faults. Side slopes are commonly of 350 to 400 metres (1,138 to 1,300 feet) with some vertical rocky cliffs up to 60 m (195 feet) high. The topography of the area is dominated by long narrow ridges and steep secondary spurs, with a high degree of rock outcrop on ridge crests, slopes and stream channels. Lower Ordovician sandstones and mudstones intruded by numerous small quartz veins form the dominant geology. The river descends steeply through boulders along a convoluted course with several steep-sided gooseneck meanders.”

  9. Ron Schott says:

    Oh, there also appear to be some extensive aggregate(?) quarries just south of the WoGE #183 area on the north edge of the town of Darley, Victoria.

  10. Chris Rowan says:

    The elevated region is actually a lava flow, and this is an example of inverted relief: the lava originally filled a paleovalley, but because it is more resistant to erosion it was left standing when the surrounding topography was eroded away. This paper discusses the Bullengarook lavas in the context of interpreting similar features on Mars.
    Clearly my co-blogger’s obsession with river/basalt interactions is less obvious than I thought. Does this mean I have to tease her less about it?

  11. Edward "Digger" Cavanagh says:

    Nah mates! Get out your pans. Heaps and heaps of gold there, I’m sure of it.