But these processes are unlikely to produce large-scale ice accumulation far from the volcanic source. And finally, a less likely though possible explanation is that rootless cone formation on Mars ...

That feature is Athabasca Valles, a system of valleys carved into volcanic plains ... and seeing rootless cones on that lava tells scientists that there was ice underground but very close to ...

But these processes are unlikely to produce large-scale ice accumulation far from the volcanic source. And finally, a less likely though possible explanation is that rootless cone formation on ...