Re: Hoagland and Bara strike out
Interestingly Hoagland and Bara mention the scarp aorund Olympus Mons. Thomas Gold theorised that glaciers came up to this level and magma on hitting the level of ice created this shape. He also thought that many of the river shapes could have been streams underneath sheets of ice.
Most of the rest seems to be taken from Tom van Flanderns's book, so I don't see what they are taking credit for.