This Hirise image shows pit craters in Alba Patera due to volcanic collapse:

Pit Craters on Alba Patera (PSP_005071_2150).
http://hirise.lpl.arizona.edu/PSP_005071_2150

Notice that part of the rims have a scalloped quality, similar to Victoria crater, though with Victoria this is more extreme and uniform.
Perhaps this is a diagnostic feature of volcanic collapse craters.
I had speculated that Victoria might be a volcanic collapse feature because of its scalloped rim here:

A volcanic crater in Meridiani, Mars.
03-October-2006, 06:01 PM
A volcanic crater in Meridiani, Mars.


Bob Clark