Impact crater? What do you think?

[mistermack]

I think I might have identified a previously unknown impact crater, in the north of Russia.

I saw it on Google Earth and it looks uncannily like something big splashed down.

I've checked on the database of known craters, and reported ones that haven't been verified, and it's not listed in either.

It's about 8km across, in an area of no roads, so virtually nil chance that it's man made.
It looks like layers of sedimentary rocks were pushed up in a ring, and then worn flat by the ice, so that the layers point upwards in a ring.
Have a look and see what you think :
https://www.google.co.uk/maps/@70.91981 ... !1e3?hl=en
If it opens in map view, you might need to click on the "Earth" box to change it to Earth view to see it.

[L'Emmerdeur]

Could be an impact crater, or it could be an ancient methane "blowhole", or something else. It reminds me a bit of the Richat Structure.

[pErvinalia]

I think I might have identified a previously unknown impact crater, in the north of Russia.

I saw it on Google Earth and it looks uncannily like something big splashed down.

I've checked on the database of known craters, and reported ones that haven't been verified, and it's not listed in either.

It's about 8km across, in an area of no roads, so virtually nil chance that it's man made.
It looks like layers of sedimentary rocks were pushed up in a ring, and then worn flat by the ice, so that the layers point upwards in a ring.
Have a look and see what you think :
https://www.google.co.uk/maps/@70.91981 ... !1e3?hl=en
If it opens in map view, you might need to click on the "Earth" box to change it to Earth view to see it.

Google threw an error. The cover up has already begun...

[cronus]

If it is a impact crater that is no real surprise for a planet this lucky.

[mistermack]

If it is a impact crater that is no real surprise for a planet this lucky.

That's true, you only have to look at the moon to see that.
But most of ours are now well hidden. There are less than 200 identified and confirmed, so it's probably worth somebody checking it out.

I had a look at the website that keeps the list, and very few of them are as clearly defined as this.

I would probably discount a methane blowhole, as the area is so rocky and you can see sedimentary layers exposed. The methane blowholes are much smaller. This is 8km wide.

It could be volcanic, you would have to be a geologist to give an informed guess.
I would say that impact crater is the most likely cause, but you would have to collect rock samples to confirm it.

One thing that did occur to me was that it might be an ancient lake, that created multiple shorelines over the ages, as the water level varied. There's a place in Scotland that that happened. But it would have to be a real fluke, for the lake to be so circular.

[rainbow]

The methane blowholes are much smaller.

[pErvinalia]

It's actually a raised mound, not a depression. There's streams flowing off it into the bigger rivers surrounding it.

[mistermack]

Yeh, I noticed that.
If you imagine a huge sheet of ice, sliding over a fresh crater, it's going to grind down the raised walls and deposit debris in the crater, so after a few cycles it would end up flat, but with different looking rocks in the middle, to the outer ring.
The centre seems to be looser fill, because the streams have eroded little canyons in it, on their way out. That's in keeping with the ground-up shit from the bottom of an ice sheet.

[PsychoSerenity]

You could try asking Mr Putin. http://en.kremlin.ru/contacts

Or go for a really long walk.

[mistermack]

I'm suspecting it's a granitic intrusion from below, that pushed up the layered rock around it's base, and with erosion, the eroded edges of those layers came to show as concentric rings.

If the intrusion was a circular bubble, that would do it.
One type is a lacolith, as shown below with an example from the US. It looks a good candidate :