Crater in NE Canada?

I was skimming a large North America map earlier today and noticed a circular river (or perhaps it'd be labeled a lake with a large central island), in North Eastern Canada. The lake/river has a diameter (stretching across the island) of about 45 miles.

external image

I was wondering if this type of geological formation would be formed by a large impact crater gradually filling with water over time, or is this simply an oddly shaped aquatic feature?

*Note: If you care to take a look yourself, the coordinates are in the lower left hand corner of the picture.

[Mod Edit = Please review: ATTN: Image Size Guidelines Image now links to full size version]

[edit on 4/2/06 by JAK]

You got that right, it's the Manicouagan Reservoir

There are quite a few others in Canada too. The harsh winters have preserved them, more or less.

on a map you can find a trail of craters where a comet like shoemaker-levi 9 did to jupitor. it's always show on discovery, tlc, or ngc when they do asteroid bits.

an interesting side note is that one of the oil fields in mexico was created by the fracturing of a asteroid impact. i wonder if anone has drilled around this site?

[edit on 4-2-2006 by bigx01]

Here is another crater in northern Quebec.

Google earth link: www.image-du-monde.com...

Pic: www.uqtr.uquebec.ca...

Here is another crater in northern Quebec.

Google earth link: www.image-du-monde.com...

Pic: www.uqtr.uquebec.ca...

Canada has a lot of craters in it. Of the 30 largest craters on Earth, being in size of 20 or more km in diameter, Canada has 10 of them. The largest being about 250 km in size.

First person to find them all wins a prize!

EDIT:

As for a crater chain on Earth, I couldn't find much. This was the best of which I found:



[edit on 2/6/2006 by cmdrkeenkid]

Heres a database of all know earth impact Craters

www.unb.ca...

Thats indeed a impact crater shows up " Manicouagan Quebec, Canada 100.00 KM exposed N 51° 23' W 68° 42' " in the data base. Third largest in North America

I don't have the patience to find them all, but for those who do the breakdown goes like so:

Manitoba - 1
Saskatchewan - 2
Quebec - 4
Ontario - 2
Newfoundland - 1
Nova Scotia - 1

The Manicouagan is the second largest, the Sudbury, Ontario one is the 250 km.

10/30 Largest Earth Impact Craters In Canada (no specific order)

1. Carswell Crater in Saskatchewan, Canada
2. Charlevoix Crater in Quebec, Canada
3. Clearwater East Crater in Quebec, Canada
4. Clearwater West Crater in Quebec, Canada
5. Haugton Crater in Nunavut, Canada
6. Manicouagan Crater in Quebec, Canada
7. Mistastin Crater in Newfoundland/Labrador, Canada
8. Montagnais in Nova Scotia, Canada
9. Presqu'ile Crater in Quebec, Canada
10. Saint Martin Crater in Mantioba, Canada
11. (Just in case you don't want to count Clearwater West and East as two seperate craters) - Slate Islands Crater in Ontario, Canada

I'm not sure that there are 2 over 20 KM in Saskatchewan

Isn't the circular formation located on the lower part of Hudson Bay the biggest astrobleme on Earth (the one on the Yucatan Pennisula might be bigger)? I'm not really sure but it was considered to be an impact site if I can remember. Astroblemes are scars left behind by impacts.



It has a diameter of about 275 miles. You may also notice alot more craters on this map just east of the circle in Quebec.

GoldEagle

Yeah, I would count them as one... Close though, as you're missing the BIG one.

GoldEagle, I don't believe that that's a crater though. I've never heard it called one before, thought it may be worth digging in to. Those islands in and near the center of the circle could be the results of a complex crater.

The big one would be

Sudbury Ontario, Canada N 46° 36' W 81° 11' at a whopping 250.00 km. Larger then even the KT impact crater in Mexico

Right?

Right! And yeah, it's over 100 km larger in diameter.

Man that must have been one heck of a explosion. A bad day for anything on earth at the time that hit. Well atleast if you were any where near ground zero you likely wouldnt even know what hit you as you were vaporize.

I did a bit of digging around in my large book collection to find info on it and all I found was a single article in a "Time Scientific Library" book called "Planets". It claims that it is the worlds largest impact site. But there is a bit of a catch... the book was published in 1966! It said that it is the world largest (at the time) impact site and it is confirmed to be an impact. I'm going to look around more for it, but over the years someone may have proved it wrong.

It has the charactristics of a crater, raised centre (islands), rings of islands around the crater, other craters in Quebec seem to be secondary impact sites due to there proximity. It certainly looks very out of place.

I'm not going to jump to conclusions until I find more on it.

GoldEagle

[edit on 2/6/2006 by GoldEagle]

I'm sure I can't add properly.

You're right, that should have been one crater for Saskatchewan.

Winter doesn't preserve anything except things which need freezing to prevent rotting.

Freezing water grinds top of bedrock very effectively and can literally split stones in half, only hardest and least porous rocks can withstand it without fast eroding.


Reason's for amount of craters in Canada are entirely others, first of all it's very big country.
Then even more important thing considering big hits is that parts of Canada belongs to group of areas with very old continental crust. (impacts, especially bigger, were more common earlier history of Earth)
And this old means place where 1.5 billion years old rocks are young ones.

en.wikipedia.org...
Other similar area is Baltic shield.
Both of these areas are some of the oldest continental crust parts and contain remnants of ancient mountain ranges similar to Rocky mountains, Himalaya, Alps... it's just that those mountains have eroded away and now there's only "roots" of them left.

Here in Finland problem is that bedrock older than 2 billion years old has been involved in so many folding and faulting processes that possible older craters have been destroyed about completely. (lines show just biggest faults and collision zones)

If someone wants to practise finding craters from satellite photos craters in Finland should show nicely what eroded craters can look.
maps.google.com...

Also I've read one book in which it was listed as possible crater.

Finding signs of impact should be easy... Glaciers have even scraped away any softer material from top of bedrock so there shouldn't be much digging required.


For that sized crater there should be plenty of visible signs in rocks, actually the bigger the crater the stronger the signs are.
And signs stay in bedrock much longer than eroding crater bowl takes...

Here's some pics of shatter cones from "crater" which might be just base of central peak.
www.somerikko.net...

That island chain along coast could be explained by multiple rims.
But those islands inside it are such that it would require quite big central peak, neither they are in center... but impact in shallow angle can cause such. (but then again rim seems to be very symmetric)

Also on other hand it should have been very easy to find proofs for it being impact crater considering size.

I got a list of all the big known impact sites in the world here:

www.unb.ca...

The largest currently listed is in South Africa. The one in Sudbury is probably a good part of the reason the world's richest nickel mines are all there.

There's still some debate about Hudsons Bay, if it is, it would be the largest in the world at 440 km across, but there's no other surface stresses outside of that area that would indicate a massive impact. The lack of evidence doesn't rule it out either though.

That definitely isn't full list, it lacks at least other "half" of Suvasvesi double crater.
Here's little longer list including some meterite falls and known airblasts.
www.somerikko.net...

And list of suspected craters plus structures with other reasons than impact more propable.
www.somerikko.net...


Wikipedia lists one very big hypothetized crater called Shiva in West India but that size impact would cause huge ejecta layers

While moon has plentiful amount of big hits problem for finding those in Earth is erosion and tectonic processes, most of moon's craters are billions years old but lack of these processes has preserved them.
Also oceans cover over two thirds of Earth and when you remember that oldest sea floors are just few hundred million years old because oceanic crust is in slow constant "circulation" where new crust is created in middle ridges of oceans while oldest parts get subducted under continental crust and back to mantle it's clear that this process alone has destroyed big amount of craters.


For example here's map/list of known and suspected craters/structures in Fennoscandia... problem is just that these areas have been treated in such way that finding any proves to direction or other from old (and big) structures would like trying to recognize make of car crushed between two colliding trains.
www.geophysics.helsinki.fi...




Speaking of that when you look map of previous link and crater/structure number 88 and compare it to satellite photos available in here there's very clear semi circular structure there.
Also this place has considerable nickel concentrations, in fact there's city named as Nickel because of mines.
While most of this area contains lot of minerals rocks crushed porous by impact could well provide good base for enriching of certain minerals by geological processes.



Also there seems to be other suggested reason... basing to fact that lower crust contains more minerals.
www.news.utoronto.ca...