Lol Sudbury, I know what a magma chamber is and a bit about how they form BUT I (
engineer that once was going to be a chemist, helps but not enough) am probably just as
in the dark as you.
If you look at a topographic map of the Ring, you see a circular fault line. I suspect
there was a meteor impact followed by vulcanic intrusions. So the path along the Ring should have similar traits, imho.
I presume that due to the initial event being meteoric instead of volcanic that any 'Chambers' would be quite shallow, by that I mean one or two kilometers as opposed to several or tens.
Mind you I have no knowlege of the local geology but am just posting how I visualize the region.
Hope someone will correct me on anything I have erred.
Tia, Ed.