A bit of a stir at the conference. Phil Christensen has shown that in some areas of Mars, the majority of small craters are secondaries, related to a single very recent impact. He suggests that the break in slope of the cratering function measured for both the Moon and Mars is the break between primaries and secondaries. This may make some apparently young surfaces even younger. OTOH, it may be already included in the way that ages are calculated and calibrated to the Moon.
Unfortunately, none of the crater-age experts were in attendance, so I think we'll have to wait till the next conference to see a reply from Bill Hartmann or Gerhard Neukum. LPSC should be the place for this, in March. Abstracts are due December, so the parties have time to marshal their forces for this.
Space/Science » in reply to Dating and radiation environment?
Mars Crater Ages Debate