I have read the online LPI report.
Icarus is not a journal easily available from my area. I haven't seen the Icarus report.
These results were based on at best 25m/pixel Viking images. MGS images have led researchers to conclude young volcanic flows extend to within 10 million years and perhaps to current times.
Mouginis-Mark based his conclusions on the fact that the channels he saw were on top of the youngest flows then known based on Viking era images.
I'm thinking that the same conclusion will hold when the MGS images of these areas are seen, i.e., the channels will be seen on top of the flows dating to within 10 million years and perhaps to current times.
Note well that this same conclusion has already been made in regards to water in Athabasca Valles in the Cerberus Plains, also a near equatorial region:

Floods At Mars' Equator Appear To Be "Recent"
by Lori Stiles
Tucson - Feb 20, 2002
"UA Regents' Professor Victor Baker and others concluded from Viking spacecraft images more than 20 years ago that great water floods must have carved huge channels draining into another region of the planet, Chryse Planitia. But photographic evidence consistently confirms that happened more than 2 billion years ago."
...
"What's different here is that this is very recent, and the water source is nothing like we have on Earth," she said. "The water here gushed from volcano-tectonic fissures. While the fissures themselves may be older, the latest eruption of water was probably only about 10 million years ago."
http://www.spacedaily.com/news/mars-water-science-02a.html

Bob Clark