Nice maar field example!

Here's a tuff ring: Panum Crater, a beautiful rhyolite dome surrounded by a low tuff ring, on the south side of Mono Lake.

There are thousands and thousands of formations like this on Mars. Yet to date nearly all of them are routinely interpreted as impact craters. Why?

The idea that "99%" of circular formations on Mars are impact craters has become pernicious. It means that alternatives involving an active subsurface are largely ignored. It can also mean that surface ages on Mars are wildly over-estimated based on "impact" crater counts -- that count mostly vents.

An open-minded review of what we can see on the surface of Mars will show -- I believe -- that vast regions of Mars have experienced extensive relatively recent "heat release" events involving explosive venting of ice, water and steam, floods of lava, surface collapse, and so on. These events may be continuing to this day.

The idea of a warm and active Martian subsurface, however, is still generally 'heretical'. The tortured efforts to 'save the phenomena' to maintain the standard cold, dead, Lunar-like 'ice-ball' model of Mars look more and more like time serving.

The more we can point out the similarities between circular features on Mars and venting and collapse features on Earth and Venus and Io and other active bodies -- and how little these features resemble impact features on any planet -- the better for planetary understanding.

IMHO. Of course! ;-)

Cheers, BFelix