Google Earth -- Is this an ancient impact crater?

I was exploring southern New Hampshire with Google Earth and came across this structure [Google Earth required] in Pawtuckaway State Park that looks strikingly like the ancient remains of a terrestrial impact crater about 1 mile across, with a central peak. But I looked it up on The Earth Impact Database, and it is not listed. So is it just a coincidentally round structure, or might it be a previously undiscovered impact crater?

If it is, do you get to name it??

It looked like an old caldera to me, and a bit of googling about suggests that Pawtuckaway had volcanic origins:

http://nhgeology.org/jurassic.htm

From the section on ring dikes.

Google Earth community has a tag which says the following :

Agrees with yabob’s post.

Thanks yabob, ring dike it is. Armed with the correct term, I have found lots of information on Mt. Pawtuckaway. I may take a drive up there this weekend and check it out. Based on my atlas, there is a road that circles between the outer ring and the central peak, called Middle Mountain, as well as a picnic ground and old Chase Cemetary. Looks cool.