Welcome
and yes Kemptser got it in one. They are indeed thermocast lakes caused by permafrost and we even
have them down here in Australia which indicates that the climatic conditions we have known in our
lifetime are not how it has always be. Interesting...

Are the Austrailian lakes in this post the ones you are talking about?

I recognized them too, but I've never seen them so big! They're usually called "pingos" and there are several types, and there are "palsas" too.
In the Netherlands we've got them too, from the last ice age, though they're tiny compared to these.

Hi, i'm spanish and I apologice, first at all, about my inglish, so ...

This circular lakes are just a common geological structure, (called "dolinas" in spanish ) it happend wher we have a soft layer of sand and a hard layer under it.
The hard layer may be quimikly erosioned ( karst ) and when it can't hold the sand on him, it fall off leaving a circular mark in the surface.

If the hard layer ara very erosionated it may contain water and, if the level of the water inside the rock is most elevate than the surface, it will ascend, and create a lake in the circular mark created before.

ufff. .. my inglish is really hard.. so I think that the information is right.. thanks.

you can see the image attached

That is a great explanation (the english notwithstanding) and for that
we thank you. Did your explanation contain a reason for why the result is circular, not square, not oval? Were these once eruption areas (hot springs)?

Thermokarst features are rounded because the initial formation of the feature begins at a point rather than the whole feature being created at once. The thermokarst features in question were most likely formed by ice wedges in the permafrost. In the summer the permafrost may have softened enough for water to work its way into a crack in the permafrost, once winter rolled around the water in the crack froze and in turn made the hole in the permafrost larger. Once the process begins, every summer that is warm enough to melt the ice wedge and surrounding permafrost increases the size of the thermokarst feature, usually in a uniform circular pattern around the feature, unless the melting edge reaches a more resistant soil, rock, etc. which doesn't melt as easily. If you look close enough, there are features that aren't perfect circles because of resistance to melting, but no squares.

Manicouagan, Quebec, Canada
The Manicouagan impact structure is one of the largest impact craters still preserved on the surface of the Earth. The prominent 70 kilometers (43 miles) diameter, ice-covered annular lake that fills a ring where impact-brecciated rock has been eroded by glaciation. The lake surrounds the more erosion-resistant melt sheet created by impact into metamorphic and igneous rock types. Shock metamorphic effects are abundant in the target rocks of the crater floor. Although the original rim has been removed, the distribution of shock metamorphic effects and morphological comparisons with other impact structures indicates an original rim diameter of approximately 100 kilometers (62 miles).
Location 51�23'N, 68�42'W
Age 212 +- 1 million years

More on those lakes - my suggestion is that they are kettle lakes.

Why circular? Imagine post-ice-retreat big blocks of ice left on flat ground - as they slowly melt they are subject to wind from all directions - and they have some drainage that carries silt away in small quantities. This is one of the flatest areas you can imagine, slowly rising from Foxe Basin by isostatic rebound. Look east for the old Cape Dominion, which is now reflected to the west. The lakes are very round and very shallow - about the depth of a tall human. They are inhabited by king eiders (bound for Greenland), long-tailed duck (many perhaps also Europe-bound), Pacific loons and the odd tundra swan. This area also has nesting Sabine's gulls.

here is a good explanation:

http://ougseurope.org/rockon/surface/thermokarst.asp

nice find!!!

It's a meteor crater. I'm from Quebec and I know some association that tries to conserve this monument. I'ts probably one of the oldest crater in the world.

www.soslevasseur.org